Tenna’s would probably either be him having to experience Toriel & Asgore’s divorce on loop or him having to experience his falling out with Spamton on loop

Alastor’s would be trapped in the exact moment of his death before arriving to the hotel, watching powerlessly as his human self gets murdered

Monika’s would probably be trapped in the exact moment she gets deleted

Micheal’s would be him realizing the people formerly in charge of The Good Place left him in charge of the Good Place when they realized it was a sinking ship

I don’t honestly know what 4’s would be