Soul Collector

"Warriors are often observed tracking the number of beasts or men they slay in battle. Others even take trophies, such as gold, weaponry, fingers, or ears. I posit that collecting a soul is more of the same. Besides, I have more use for it than them, surely."

-The First Soul Collector

Your Soul Is Mine

At the 3rd level, you uncover a method of draining the soul from a fallen individual. As an action, you can steal the soul from a creature who is within 30 feet of you, is currently at 0 HP, and has been placed at 0 HP within the last minute. If that creature is eligible for death saving throws, it dies. Constructs, certain animals, and certain undead do not have souls to steal, at the DM's discretion.

Upon stealing a soul, you regain hit points equal to your Fighter level + your proficiency bonus.

When you absorb a soul, you gain all of its memories from the 24 hours leading up to its death. Additionally, you can speak with any soul you have taken. While the soul can only speak to you when you permit it to, you cannot force a soul to tell you something it doesn't want to.

Might of a Million

At the 7th level, you become stronger for each soul you have recently taken. The souls you steal give you a +1 to damage rolls you make. This bonus caps at a number equal to your proficiency bonus, and decays by one point each time you take damage. The bonus fades if you finish a short or long rest.

Swift Soul Steal

At the 10th level, you can use Your Soul Is Mine as a bonus action instead of an action.

My Reality

At the 15th level, you complete the development of a pocket dimension in which your stolen souls reside. Once per long rest, you can cast Mordenkainen's Magnificent Mansionwithout material components. Stolen souls are imprisoned therein and are treated according to your whim, but they cannot harm other creatures.

Master of Souls

At the 18th level, you master the art of stealing souls. You automatically steal the souls of any creatures that fall to 0 HP within 25 feet of you without having to take an action.

You can use an action to expend a point from Might of a Million and summon a soul you have stolen in the past 24 hours. The soul appears at a location of your choice within 30 feet of you. The soul's HP value is reduced to half.

The soul follows orders you give it without question and rolls initiative separately from you. The soul can speak if you permit it to. If the soul falls to 0 HP, or if a minute passes, it evaporates. The soul is lost and cannot be recollected.

You can summon a soul one time per long rest.