Yeeeah, exactly. Are there even any evolutions that are basically Pokemon fusing together?

[Apparently he's blocked Magneton, Slowbro and others out of his mind for the time being.]

But I think you're right about the radiation thing. I can't remember a time where something like this happened, unless it happened once while I was gone or before I got here the first time...

[All he can really do is shrug.]

Guess it's a mystery?