my dad finished reading a book, and he said the ending was:
someone absorbed the powers from these children, became a god-like creature and made an alternate dimension, but after some time the children like, came alive basically killed them.
keep in mind my dad said this was one of the worst books he'd ever read
Your dad should still have a good time though just don’t show any signs of anxiety when he strays from the TRUE PACIFIST route and let him do his own thing
That’s nearly the entire premise of the first playthrough of Undertale