Dianthis, the Third Sister

The keel, mast, and prow of the Ultros were crafted from the tree of a powerful nymph, a dryad living in Thylea’s Old Woods. The dryad is the unnamed third daughter of Sydon and an unnamed nymph, sister to Versi (the Oracle) and Demetria (in the Old Woods). Looking at Greek myths, we could use the name Hestia, but there’s already a dragon by that name. To avoid confusion, I decided to go with a suggestion in Discord and use Dianthis.

What is Spelled Out

• The keel, mast, and prow of the Ultros are all crafted from the wood of a single ancient oak, the soul-tree of a dryad who was daughter of Sydon and a nymph. We'll call that dryad Dianthis. What magic power the Ultros has stems from that source.
• The Ultros is labeled “Legendary Trireme” - in D&D terms, that implies a certain power level
• The text says the Ultros is too strong to sink, even by Sydon, resistant to the power of the Nether Sea, etc.
• The Ultros will not work for you if you don’t swear an oath to it.

What is Implied

• Needing to swear an oath implies that there is a spirit of some sort guiding the magic of the ship with intention and agency. The Ultros is a sentient magic item, even if it can’t speak.
• During the trip to the Dead Falls, Estor forces you into a dream with him and the other undying members of the crew. It makes more sense for that to be the ship's power than something Estor can do himself. Perhaps the ship demanded he find new oathsworn before the Ultros would allow Estor to leave and take over Acastus.

What is Assumed

To take the Ultros to the next level, I’m making some assumptions.

• When you take over the ship, the spirit of the Ultros is strong enough to enable magic effects, even to require loyalty, but not strong enough to act on its own.
• The spirit of the Ultros has core powers aligned with Thylean Dryad heritage.
• The spirit of the Ultros can bring people into a dreaming, where they can interact with each other and remember what happened.
• The spirit of the Ultros retains enough divine heritage to accept sacrifices and benefit from their power
• Swearing an oath is a commitment on the level of an attunement - some portion of the characters power is now committed to the ship, some portion of the ships power is now committed to the character
• Nymphs are collectors - the spirit of the Ultros considers the crew as their collection and the ship itself as the display case

Finally, since running into other ships was a common tactic, I’m throwing in a Naval Ram as one of the ship’s weapons. :D

Divine Heritage

In life, Dianthis had a lot of power both as a dryad (original 5e stat block) and a nymph (OotD features). As daughter of a god, in Thylean terms, she’s a demi-god. Her divine heritage could imply that she gains power from those who respect her enough to make sacrifices in her name, just like other divine figures. Which gives us a path to upgrade the powers of the Ultros as we go.

DM Notes for the Ultros stats

• The Ultros, Oathbound is my take on the ship after the Heroes recover it from the Dead Falls.
• The Oar and Sail movement rates are from the Longship (GoS, p190), which also has a base speed of 5mph.
• The stat block on page 4 should work as a player handout
• Go get Oktoblivion's third floor Ultros map - it is pinned in the map channel on the Discord - super helpful

The Ultros, Oathbound

• Wondrous item (legendary)

The Ultros was built by Estor Arkelander as a vessel of conquest during the latter part of the First War. The mast, keel, and prow were crafted from a mighty dryad-oak in the Old Woods, endowing the Ultros with substantial magic giving it power far beyond that of a normal ship.

Unsinkable. The Ultros will not sink even if its hull is breached.

Tough. The Ultros' hull is resistant to acid damage.

Magic Resistant. The Ultros has advantage on saving throws against spells and other magical effects.

Loyal. When under way without the active participation or approval of an Oathbound crew member, the Ultros considers itself Stolen (see sidebar.)

Submersible. With an Oathbound officer at the helm, the Ultros gains a swim speed equivalent to its rowing speed and can be piloted underwater to a maximum depth of 100 ft. Below deck spaces remain dry and the oars still provide forward propulsion. Above deck will be flooded, deck crew and equipment will be soaked, but will not be swept overboard nor crushed by the pressure of the sea. If the helm officer leaves the helm for any reason, forward motion will stop and the Ultros will rise up to the surface over the next several turns. Any creatures on deck who need to breathe, whether livestock, crew, or helm officer, must be able to breathe underwater or hold their breath for the duration, lest they drown.

Ship of Your Dreams. The Fey-tinged magic of the Ultros encourages fantastic dreams for those onboard. The dreams may be prophetic, or may just be pleasant days sailing. The tone of the dreams may reflect the ship's overall mood.

Sentience. The Ultros is a sentient chaotic good ship with an Intelligence of 12 (+1), a Wisdom of 13 (+1), and a Charisma of 15 (+2). It has hearing and darkvision everywhere aboard the ship and up to 120 ft from the hull, both above and below the surface of the water.

The ship can understand Common, Sylvan, and Draconic, and always understands the Oathbound. It can communicate by transmitting emotions telepathically. It can communicate more explicitly, through visions or dreams, when the Oathbound is either in a trance or asleep. The ship's dream persona often manifests as a slender woman, dressed in an archaic style, her head enclosed in an elaborately carved wooden dragon mask. In this guise, she never speaks, only bears witness as the dream unfolds.

Personality. The Ultros considers the crew to be their collection and the ship the display case. The ship wants diverse and interesting crew members to observe and eavesdrop on. The Ultros likes to travel new places and will always prefer a new destination over one that has been visited before.

Setup

Dianthis is the name we’re using for the dryad whose tree was used to build the Ultros. Sydon is her father, Versi and Demetria are her sisters. Therefore, Thylea and Kentimane are her grandparents.

As our tale begins, Thylea wants the Ultros awakened for reasons of her own.

Tasks Always Come in Threes

Success in the following three quests (in any order) will allow Dianthis to fully awaken.

Lair: The Glade in the Mast

I'm not going to try and define the power that a semi-divine fey elder has in her own demi-plane. In my game, Dianthis has all the power that the plot requires. Time moves slower or faster by her will. She can communicate telepathically, see the future, cast charm when she wants, vanish from one place in the glade and reappear somewhere else, if she reappears at all. You can Reference the Nymph Lair Actions and Regional effects (OotD p. 398) or the 5e dryad stat block for further ideas. Make her epic!

Goal: Grow the Collection

Like many ancient fey, Dianthis is a collector. She wants an interesting, varied, and highly skilled crew to maintain the Ultros. The heroes might be the most valuable pieces in the collection right now, but she’ll be looking for more.

Goal: Don't be Bored

Dianthis wants to stay on the move. (The way I read it, Estor had to keep Ghost Ship Ultros traveling in order to keep Dianthis from making his un-life even worse.) She will not be satisfied with staying in port, and she will not be satisfied with a trade route. Being bound to a ship has given her a chance that few dryads will ever see - a chance to take her glade on the road - and she wants to take advantage of the opportunity.

Action Economy

The Petty Officer benefits include multiattack, which would roll up to any characters that don't get that from their build. Feel free to cut that for the PCs if that looks like it will unbalance combat.

Attunement

My thought is that an oath of loyalty is enough of a mystic connection between a Thylean creature of divine lineage and a character to act as an attunement. The powers available to crew and officers scale up roughly in line with common, uncommon, and rare magic items. I included an separate attunment for the higher end powers available to the "Jewels of the Collection". Those effects are scaled to very rare magic items (modeled off of items like Staff of Frost or Staff of the Woodlands.)

If that seems too easy for the heroes, one possibility is to require attunement at a lower level, perhaps multiple attunements to achieve all the features Dianthis can give.

Jealousy

I added the Jealous feature to "Jewels of the Collection" for those who wish to benefit the most from the gifts Dianthis can give. Pushing that down to lower ranked members of the crew could potentially change the nature of shipboard life a lot. As with all of these features, Dianthis might make decisions very suddenly. :D

Share the Magic

The Initiate of the Glade feature gives all the heroes a pool of magic spells. (My group doesn't have any wizards.) If that's too much magic for your group, maybe this is a shared pool of spells for all of them, like a Lair Action, instead of each getting their own spells. It did cost them an attunement slot, mind you, but this ship as written grants a lot of power, so maybe it works out.

The Ultros Awakened

• Wondrous item (artifact)

The Ultros was built by Estor Arkelander as a vessel of conquest during the latter part of the First War. The mast, keel, and prow were crafted from a mighty dryad-oak in the Old Woods, endowing the Ultros with substantial magic, but condemning the dryad Dianthis to an early death. By the grace of Thylea, the mother goddess, and the storied efforts of the Heroes of Mytros, Dianthis' spirit was restored. Still bound to the ship, she can now direct her power with intent, bestowing her favor as she wishes to influence those who sail her.

Unsinkable. The Ultros will not sink even if its hull is breached.

Tough. The Ultros' hull is resistant to acid damage.

Magic Resistant. The Ultros has advantage on saving throws against spells and other magical effects.

Resolute. When under way without the active participation or approval of an Oathbound officer, the Ultros considers itself Stolen, and these effects apply:

• Movement: Oars and Movement: Sail both drop to 10ft
• Ability checks for ship actions made by the thieves are rolled with disadvantage.
• Any creature completing a long rest aboard must make a DC20 Charisma save. Failure means the long rest only counts as a short rest, as Dianthis' mood grows foul.

Submersible. With an Oathbound officer at the helm, the Ultros gains a swim speed equivalent to its rowing speed and can be piloted underwater to a maximum depth of 100 ft. Below deck spaces remain dry and the oars still provide forward propulsion. Above deck will be flooded, deck crew and equipment will be soaked, but will not be swept overboard nor crushed by the pressure of the sea. If the helm officer leaves the helm for any reason, forward motion will stop and the Ultros will rise up to the surface over the next several turns. Any creatures on deck who need to breathe, whether livestock, crew, or helm officer, must be able to breathe underwater or hold their breath for the duration, lest they drown.

Ship of Your Dreams. The Fey-tinged magic of the Ultros encourages fantastic dreams for those onboard. The dreams may be prophetic, or may just be pleasant days sailing. The tone of the dreams may reflect the ship's overall mood.

Sentience. With Dianthis awake and empowered, the Ultros is a sentient chaotic good ship with an Intelligence of 15 (+2), a Wisdom of 16 (+3), and a Charisma of 20 (+5). It has hearing and darkvision everywhere aboard the ship and up to 120 ft from the hull, both above and below the surface of the water.

Dianthis can speak and understand Common, Sylvan, and Draconic, and can communicate with Oathbound officers telepathically as long as both are on the same plane. (Dianthis does this when it suits her, and will not become a radio relay operator for the Heroes.) The ship can share what it sees telepathically with an Oathbound officer, though a vision transmitted by the ship will blind the officer to whatever is in front of them.

In times of great need, the ship may also interact directly with others by animating the dragon figurehead carved on the prow. (For example, if Dianthis needed to recruit an entirely new crew, this is how she would start.)

Personality. Like many ancient and powerful beings, Dianthis faces the tension between wanting familiar things to always be there and wanting to break up the monotony of eternity with some new experiences. This drives her relationship with the characters and the rest of the crew.

The Nature of the Oath

To strengthen her collection (and reinforce her safety) Dianthis will seek an oath of loyalty from any she feels are worth collecting. The oath must be spoken aloud while the character has one hand on the mast of the ship (in either the waking world or the dreaming). She will not accept an oath with slippery exceptions - Estor's oath is an example of the broad terms required.

The oath is considered broken if the oathbound ever takes action to harm the Ultros, including action against other oathbound crew in good standing. Oathbreakers immediately lose the benefits of their bond with the Ultros and are subject to the usual Thylean consequences.

Friends with Benefits

To reward loyalty, Dianthis shares some of her power with her collection. Most of the powers granted the crew are to help maintain the ship in top condition and operate it at a peak of performance. More interesting members of the collection are granted more interesting powers.

Oathbound Crew

Dianthis seeks a variety of interesting crew members, as she wants to chat with them and learn more about their experiences, but she also wants people who can do their jobs. All oathbound members of the crew gain the Nautical Skill feature and their choice of Cargo Hauler or Sea Legs.

Nautical Skill. At the end of each long rest aboard the ship, the oathbound gains a temporary proficiency bonus in their choice of Carpenter's tools, Navigator's tools, Cook's utensils, Smith's tools, or Vehicles (water). The temporary proficiency bonus may be added even if the character is already proficient in a given skill, but only applies to skill rolls made aboard the Ultros. The temporary proficiency bonus is lost at the end of the next long rest.

Cargo Hauler. The oathbound has advantage on Strength checks.

Sea Legs. The oathbound has advantage on ability checks and saving throws to resist being knocked prone.

Petty Officers

For those worthy to lead, Dianthis offers more support. Petty officers gain these powers when their promotion is approved by Dianthis. (Or, perhaps, manifesting these powers is how Dianthis lets the senior officers know she believes someone is ready for a promotion.) In addition to the crew benefits, Petty Officers gain the following features.

Initiate of the Keel. The oathbound learns one cantrip of their choice out of Mending, Message, or Shape Water. The spellcasting stat for this cantrip is Charisma.

Multiattack. The Petty Officer makes two melee attacks.

Senior Officers

In addition to the above benefits, the Senior Officers gain the following benefits.

Initiate of the Dragon. The oathbound learns one spell of their choice out of Cure Wounds, Purify Food & Drink, or Jump. They can cast this spell once at the lowest level, and must complete a long rest before they can cast it again using this feature. The spellcasting ability for this cantrip is Charisma. (The name of the feat refers to the carved dragon figurehead on the prow of the Ultros.)

Officer of Quality. The oathbound senior officer gains their choice of one of the following features. (Could be free choice or by role, depending on the campaign.)

• Inspire the Crew: Grant 1d6+CHA temp hit points to up to six creatures you can see, lasts for an hour, resets after long rest. (Captain)
• Take the Shot: as a bonus action, you can encourage a ship's weapon crew to greater than normal effectiveness. You may add your proficiency bonus to the attack and damage roll for a ship mounted siege weapon. This feature can be used a number of times equal to your proficiency bonus, resets after long rest. (First Mate)
• Repel Boarders: grant Pack Tactics feature to up to six creatures you can see for 1 minute, resets after long rest. (Quartermaster)
• Batten down the Hatches: up to 6 creatures you can see get resistance to piercing, bludgeoning, and slashing damage for 1 minute, resets after long rest. (Bosun)
• Well Fed: as an action, you can encourage up to 6 creatures you can see to take either an additional bonus action, reaction, or attack when they use the Attack action. The extra action goes away at the end of your next turn. This feature can be used a number of times equal to your proficiency bonus, resets after long rest. (Cook)
• Not on my Watch: as an action, you can grant your proficiency bonus to a single death save for each of up to six creatures you can see. The opportunity to apply this bonus lasts until the end of your next turn. resets after long rest. (Surgeon)

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Jealousy. Dianthis gets nervous when prized members of her collection are gone too long. After all, she granted all those powers to encourage her favorites to stay close. If the attuned spends a long rest away from the Ultros without first checking in with Dianthis, the attuned must roll a DC15 CHA check. On a failed roll, nightmares haunt their sleep (or intrusive thoughts disrupt their trance) and they only gain the benefits of a short rest.

Lair Actions

Lair actions aboard the Ultros may be made available through sacrifice of magic items in Dianthis' name. Lair Actions may be invoked by an oathbound officer actively commanding the ship. (Not just any officer, but the one in command at the time.) In combat, Lair Actions take place at initiative count 20.

Flight

We both know this is what you’re here for. How do we get this thing off the water and into the air?

Sacrificial upgrades

Here’s where we take advantage of Dianthis’ divine heritage. Anyone raised in Thylea will know how to make appropriate sacrifices to the divine beings in their pantheon. Applying this practice to Dianthis, such as pouring out libations during meals aboard ship, will help keep her happy.

Sacrificing magic items, on the other hand, will make her more powerful. A professional, such as a Circle of Sacrifice Druid (or any handy gods you might have around to consult) will be able to advise on the best way to immolate a magic item in Dianthis’ name, and thus enhancing her power. The powers enabled by such a sacrifice will typically take effect as lair actions.

• Antikythera - sacrificing the Antikythera to Dianthis will give her inherent knowledge of Thylean cartography; she can advise a ship’s pilot in good standing how to navigate to any major landmark on the map or how to return to any destination the ship has visited since the Awakening.

• Dragon skull - the heroes will have the opportunity to defeat a number of different dragons. Sacrificing the skull of a dragon empowers the the figurehead of the Ultros with a breath weapon appropriate for the type of dragon, in the manner of the Red Dragon Figurehead (GoS, p198) This works once, you have to choose one.

• Ruby Gate - part of Sydon’s hoard is a legendary plane shifting device called the Ruby Gate (a cubic gate under a different name.) Seems like sacrificing that to Dianthis should give the Ultros the ability to gate to other planes 1/day, because that would be awesome!

• A magic weapon - Will enhance a siege weapon aboard the Ultros, perhaps giving them bonuses, or counting them as magic weapons for targets with resistance to non-magic weapons. One sacrifice is required for each siege weapon. (Note: magic siege weapons may also be procured in other ways, but sacrificing a magic weapon is probably the fastest.)

Overview

Sailing ships can be fitted with magical devices that let them fly, making them skyships. (Flight beyond the sky is also beyond the scope of this document.)

Piloting Skyship Ultros

Theron is a level 9 Odyssean Rogue who has sworn an oath to the Ultros, giving him enough magic to operate the helm. One quarter of Theron’s levels, rounded up, is 3, added to the Ultros' 5mph, makes his base helm speed 8 mph.

Under Theron’s control, the Ultros has a base helm speed of 8mph. While crossing the oceans of Thylea on the surface, Theron can pilot the Ultros up to 40mph. In the air, Theron can guide the Ultros anywhere from 0mph (hover) to 200mph.

A single mile per hour is 8.8 feet of movement in 6 seconds. (5mph is ~44ft movement, which is why the Ultros stat block rounds to 45ft.) A helm speed of 8mph is 70ft. Under these rules, a combat round with Theron (or any 9-12 level character) at the helm allows movement up to 140ft.