[Accelerator's been leaning against the wall of the office listening in quietly, when the topic of causing pain comes up, piquing his interest more than before. He thinks back a moment to a couple of months earlier, when the NPCs had completely gone batshit, and he'd come across Kohaku after the guy had snapped.]

I don't know about making anyone relive actual injuries, but there's at least one idiot-turned-NPC here who's so disgusted by the NPCs that he ruthlessly massacred them once just because they pushed him over the edge. Killing or injuring him might actually be worth trying.