@firechikara It's possible that the current translation is what the artist was going for. With that said, I'd expect "Ты чё?" in this situation, which can mean "What's up with you" or "What're you doing?". "Да ты чё", which is used here, normally has a different meaning, though. Depending on context and the way it is pronounced it can express a number of things, from genuine surprise (something like "You're kiddin'!"), to disbelief (especially when one suspects that the other person is intentionally lying to them, in which case it is something like a sarcastic and rather rude version of "Yeah, suuure"). Now that I think of it, it sort of makes sense if the phrase is intended as a response to Inazuma, in which case the whole thing would basically mean - Nanodesu! - Really?!