Take Over: Devil Soul

Take Over: Devil Soul (接収悪魔ソウル Teiku Ōbā: Akuma Sōru) is a form of Take Over magic that allows the user to take on the form and abilities of assimilated demonic beings.

Description
Take Over: Devil Soul is a pretty straight forward form of Transformation Magic that grants the user the ability to assimilate demonic creatures and use their powers as ones own. Devil Soul is generally considered to be the "perfected" form of the Satan Soul for two specific reasons. For one, Satan soul targets a very certain "demographic" of what is considered to be demonic, Devil Soul has no such distinction. Anything that can be considered demonic, even vaguely so, can be assimilated by the users of this magic. This was once demonstrated when a user of this magic was able to claim the soul of a human who was so sinful, so vile, that the individual's soul could barely even be recognized as a human being's anymore and grazing the lines of the demonic.

Secondly, while the original Satan Soul requires the users to possess something known as a "Demon Factor" in order to maintain control over the demons that they assimilate, a factor which only a few select people in the world is born with, rendering the magic absolutely unusable for a majority of mages. Devil Soul on the other hand is a vastly more available form of demonic Take Over, however, it carries with it a colossal risk. Compared to other Take Over magics that only require the user to "conquer" the target once and then it is under the user's control, the demons assimilated by the Devil Soul can always, and will always, attempt to overcome the one who took their souls and claim their body as their own. Only someone with great willpower can and should ever attempt to utilize this magic, and even then, it may lead to multiple uneasy nights.