DNPCs...

[Foxiekins]

I didn't see anything about this in the FAQ, but can two NPC characters have each other as DNPCs...?

Like, say I have a pair of Villians... He feels he has to look out for her because she's a girl, while she feels she has to look out for him because he's an idiot...

Both would be As Powerful DNPCs, unless that's not legal...

[Steve Long]

Sure, in theory that's possible, though in practice it may not make much sense. Usually it's best not to have any two characters, non-player or otherwise, mutually be DNPCs.