"It removes their memories and personalities from their body and puts them into my former one while I take over theirs. The transfer, for ones unused to it and so laden with emotions, tends to drive them insane and they end up dying relatively quickly. Whether from my former body degrading to a point that it can no longer sustain itself or from causing too much harm to themselves in their panicked and disorientated state. I only had one survive for longer than a few days following. He eventually starved to death as he stopped accepting the food I left him."