There is no concept of time inside the Prison Realm. Just as a certain white-haired sorcerer was about to get so bored he could grow mushrooms, he heard a voice that shouldn't have been there.
The voice asked him, "Want to play together?"
You can't pass up good food, or fun, so the strongest sorcerer immediately accepted the voice's invitation.
And so, under the guidance of a KP who called itself the System, he began a new life as an NPC in other people's tabletop games.
The players in these games always get up to all kinds of things.
One investigator held his hand and declared with heartfelt sincerity, "Teacher, I'm your dog!"
Another mistook him for the story's BOSS and tried to stab him in the back, only to be killed in a counterattack.
Yet another was more villainous than the villain, turning the whole story upside down without the real BOSS even lifting a finger...
Even without his Six Eyes accessory, 5t5 still had cheat-level stats: "Got it. So my job is to rip up the investigator cards of these unruly players who bully my coworkers (the NPCs)!"
KP: "No! Stop! I just want to run a nice, peaceful game!"
Theme: Gaze into the abyss, and see the truth.