I never thought about where this -ich in the father's name comes from 🤔 It would be logical to just write something like Ivan Ivan. Probably it's something like 's in Old Slavonic, but I'm not entirely sure.
Discussion
that's probably why i never had anyone explain it but i had two yugo friends, one was mikic and the other was marcetin and my half russian half ukrainian hobo buddy in amsterdam was a doronin
also, idk which exact language you are from but the yugoslavian form and from what i've heard of russian of the same phoneme is a slightly softened sound, you already have the ch in the form of this letter Ч