Not my problem. And since demons that aren't Kishin don't seem to be a part of this world either, then it's not your problem either.

[Obito waves a hand lazily.] That's your opinion. Until I see one that fits that description back at my home, I have no need to believe in them, whether they really exist or not. And if they work based on whims, then what's the point in caring about them anyway? They obviously don't care about us. Which is at least something we can say about Shinigami-san. [That kid does care, even if it's technically his fault they were here and in danger in the first place.]