My thoughts from the chat:
BT is of deity status. His "domains" include chaos, mayhem, and nightmares. He is of the BrikVerse.
NBT is also of deity status. She's the patron saint of QuikWars. She is of the NegaVerse.
Differentiations in quality (read: universe) don't matter to BT. He's batshit crazy, chaotic, and has already shown a disdain for purity.
They may not matter to NBT either. She plays it quick and dirty. She's underhanded and has already shown her willingness to sink to new lows.
They are each atypical members of their respective universes. So, in that respect, there's really no barrier to a merger.
mgb noted, however, that they couldn't be married to one another because of their Heroic Egos. So, we have to question whether or not deity level characters have an Ego. Did they ever have one (that is, were they ever Heroes)? If they did, did they transcend their Ego? Or did it just get bigger (becoming a Godlike Ego instead of a Heroic Ego)? If they still have an Ego, would it prevent either of them from working with one another? Would they suffer normal Crankiness or Godlike Crankiness? If they suffer from the latter, what would be the effects?
Then, assuming they could somehow work together (maybe they're putting their Crankiness aside to take advantage of one another or maybe they really do love one another *cough*), what would be the mutual benefit outside of generating more chaos? That is, is MOAR CHAOS enough of a motivation? If its not, what other reasons might they have for wanting to take advantage of one another? If there are more layers to the story, it might make the idea more attractive.