Let me remake the title
What if an SCP Apollyon class was release uncontained in another world.
the MC is a SCP type danger and you watch their adventure how they destroy the world full of magic, dragons, gundams, robots, gods, dimensional being, Lovecraftian Horrors and other unexplainable beings in their adventure.
all, I'm going to say is, it's quite bizarre.
you don't read this for the story,
because most of the scenarios or MC adventures, are all premise of the unpublish work of the author.
and oh, this is set in the same world as My Big Sister Lives in a Fantasy World.
so meet a lot of over powered beings.