I'm looking for a single word (or two words) that means something along the lines, "Two bad things coming together to make something good." When I say things it could mean events or objects or people or anything, that part is quite flexible. But it has to be a combination of *two*.

Alternatively I wouldn't mind a word that would mean something like, "two bad things combining to make something far far worse" either.
Thanks!

EDIT: It needs to be obvious that two *bad* things are combining. Also I can't use a phrase. I'm hoping to convert the word/2 words into a name, so that should help understand what I'm looking for.