Powers that the imprisoned possesses are as follows below
Tentacles: the corrupt substance on his back is able to be manipulated into crude shapes such as tentacles, spikes, and a wall too, the sharpness can vary by his liking
Decay: if he specifically Stabs his target 4 times in the chest, he is able to decay any life form he has in hold and take its life energy, making him stronger, faster, and smarter
Control: if the imprisoned is locked onto one target specifically, he is able to control its emotions and feelings, being able to cause physical and mental pain, if he is even locked in enough, he can be able to put them in a coma or even kill some people that they find significance
(NOTE: he is highly persistent and will track down anyone he needs to kill)