once he got triggered and you just keep afking in the game without spawning him, lets say whole day, would still be able to spawn him when you come back?

asking for a friend who wants to sleep and get anni when wake up

You can AFK once per game. So if you leave the game on in Hell act and go away for some hours if, D clone popped he will be in there as long as no one killed him. Now if you kill him and stay in same hell game he will not pop again even if the message appears.

I have done this and he has spawned at a super-unique while I'm afk. I get back and have to hit up a bunch of super uniques before I find him.

It should spawn on the first super unique that you haven't scouted yet

Literally the first super unique alive when leaving town. Blood moor? Check den. Stony field? Raka is the way! Fridges Highlands! Eldritch it is! If you’re spawning it somewhere else you’re just giving yourself more work to do finding him. I always go the Eld route! Easiest one for sure.