a lot.

As in...he is now confirmed to have a truly abusive parent (specifically his mother) and not just one who treats him like sh*t. The one who treats him like sh*t is his sister and that's because she agrees with her mother on almost everything but is just too kind to go and beat her brother.

And in the Pokémon universes, his multi-colored irises were caused by an argument he had with his mother that turned violent. The family's pet Sylveon was forced to Dazzling Gleam him (he already had slight vision problems) and the attack severely damaged his eyes (as in he's almost legally blind), - also interfering with the pigment of his irises because darn it, it's a Fairy-type move so why the heck not.

In the PortalAU, the detail is pretty much exempt, though you see it in his last seven days of life, where he is legit legally blind and his irises are (indeed) shifting colors on his emotions because of the serum's effects.

In a normal/non-magical universe, I...can't decide if we should follow the route of "the serum actually kind of worked and didn't kill the kid" or if I just need to figure out something else.