Goonya Monster: The unbroken bond

As of late, Monsters have begun to rampage throughout the world in increasingly staggering numbers.
However, one day changes everything when a boy comes across a cat.
Why does it feel like he's seen it before?
And what is that strange urge he feels?
What could be inside of him that wants to be let out?

A Goonya Monster AU-rewrite in which everything is pretty much the same... Except Goonyan is a normal cat and Octo is a half-Monster boy who doesn't remember a certain part of his life. Contains all spoilers for all six Episodes of the game, with some changes to fit the AU. Warnings for body horror, referenced near-death or actual death, and referenced serious illness

Some concepts belong to @GaiaKoraidon

Also on AO3