Although I have yet to watch Hibiki, I'm gonna go with Zanki. Nothing against Hibiki, but Zanki seems like a capabe father figure as well. He sure helped Todoroki grow up throughout the show
Hmm I think Zanki is more suited in a mentor role as seen where he guides Todoroki grow as an Oni. If we're talking about raising a kid then I'd stick to Hibiki.