Mutant - Fighter Subclass
A Mutant has been severely altered by alchemical products. Whether it was an illness that required extensive medicine to cure or an injury that wouldn't heal without an expansive variety of potions, Perhaps you were born this way. Any number of things could have triggered a severe physical or metabolic change. You decided to focus on the Mutations that reside within you, granting you abilities that exceed those of the normal adventurer. As a Mutant, and cast aside by most of the world, you stick to your training, and continue to work on your martial skills... particularly with a weapon that allows you showcase your ability to get the job done.
Subclass Features
3rd Level - Potion Habit
You have a bit more experience with alchemical concoctions than you would care to admit.
You can use a potion as a bonus action. You also gain resistance to poison
You can apply this feature to any single use consumable item at Level 10
3rd Level - Martial Prowess
Your mutations have granted you enhanced martial prowess.
At 3rd Level, Once per round of combat, you can choose to add an additional 1d8 to a weapon’s damage. -- This damage increases to 2d8 at 7th level, 3d8 at 10th level, and 5d6 at 15th level.
7th Level - Heightened Senses
You have developed mutated senses, which makes you more alert of your surroundings.
At 7th Level, Your darkvision increases by 60 feet and you gain advantage on perception checks based on smell and sound.
10th Level - Relentless Attacks
Your continuous adaptations have made you more lethal in combat.
At 10th level, Once per round, Whenever you successfully land an attack with a natural roll of 18-20 you take one additional attack as part of your attack action.
15th Level - Unyielding Resistance
At 15th Level, You have advantage on Constitution checks and saves. You also gain immunity to poison and the poisoned condition.
18th Level - Superior Focus
With that last attack, your inhuman focus has spotted a temporary weakness in the target's defense
At 18th Level, When you deal damage with Martial Prowess, the target has vulnerability to your next successful weapon attack against it this turn. If the target has resistance to your weapon, it loses its resistance instead. This does not affect immunities.
