Fabius Bile

Fabius Bile is a character.

He was once an apothecary of the Emperor's Children Traitor Legion, but has since left the legion. Fabius dabbles in genetic engineering and helps the Traitor Legions recruit new members in return for their protection. After the Horus Heresy, he worked to unlock the secrets of creating Space Marines. After narrowly escaping the Space Marines of the Salamanders Chapter on the world of Arden, he now resides on a Crone World where he continues his unethical experiments, creating mutated super-soldiers and other foul things.

Fabius experiments on himself via his Churgionen, an Arcaic device fuelled by Warp spawned fluids, resulting in vast variations on his strength and other abilities. On the battlefield, he might also bestow the questionable gift of his enhancements to others, with uncertain results. Sometimes the experiment is a success, creating psychotic killers superhuman even in comparison to their corrupted Chaos brethren, but sometimes the subject's metabolism disintegrates in the face of the stress, resulting in instant death.

Inspiration-wise, Fabius is something of an amalgamation of various "mad scientist" figures of both reality and fiction, from Josef Mengele to Victor Frankenstein.