Okay, so the basic Idea of this is that instead of the core being stabilized by Gaster, at the cost of his life, Gaster funneled the explosion out through the barrier, shattering it, but also basically making the magic nuclear apocalypse. Humans are either dead or mutated into part-monster mutants. Asgore died in the blast and toriel is now queen.
RULES *yes, it's the apocalypse, but we need them*
No swearing/sexuality
monsters allowed, humans...err, well you have to transform them into mutants, give them some extra abilities or some kind of physical diffrence (EG horns, extra eyes)
NO GARY STUS OR MARY SUES!