Charge Blade
armour (shield), weapon (shortsword, greataxe), legendary (requires attunement)
This sword and shield combo stores energy in elemental phials. They can be combined to create an enormous axe and unleash a devastating elemental attack.
The sword and shield are magically tethered and cannot be wielded separately.
Sword & Shield Mode. While in Sword & Shield Mode, the wielder of this weapon is equipped with a +1 Short Sword and +1 Shield. This is the default mode.
Elemental Phials. This weapon can gain charges while Sword & Shield Mode is active. Each time a hostile creature is hit with the Short Sword or this weapon's wielder is hit with an attack from a hostile creature, this weapon gains one Elemental Phials charge.
The charges expire after 1 hour and a maximum of 6 charges can be stored at a time.
For every 3 charges of Elemental Phials, this weapon gains a +1 to hit, damage, and AC bonus.
When attuning to this weapon and on a long rest, the wielder can change the damage type of Elemental Phials to Acid, Cold, Fire, Lightning, or Poison. The chosen damage type only applies to the bonus damage granted by Elemental Phials charges, and Elemental Discharge.
Axe Mode. While this weapon has at least one Elemental Phials charge, the wielder can activate Axe Mode using a Bonus Action. This transforms the Short Sword and Shield into a Greataxe.
While in Axe Mode, the wielder can use a Bonus Action to activate Sword & Shield Mode.
When switching modes, the number of Elemental Phials charges remain unchanged.
The bonuses to hit and damage granted to this weapon by Elemental Phials charges, remain active in Axe Mode but not the AC bonus.
While in Axe Mode, no additional Elemental Phials charges can be generated.
Elemental Discharge. While Axe Mode is active and this weapon is used to make a melee weapon attack, the wielder can force any creature in a 15ft. cone to make a Dexterity Saving Throw(DC equals 8 + wielder's proficiency bonus + wielder's Strength modifier).
On a failed save, it takes 1d6 damage per Elemental Phials charge of the Elemental Phials type.
On a successful save, it takes half damage.
When Elemental Discharge is used, all Elemental Phials charges disappear and Sword & Shield Mode is activated.

Created by u/Plenty_Goose5465 & u/TheRedDevil7494