Japanese honorifics

[empty_mirrors]

I'm looking for the correct, or most effective use of first name/surname + honorific to project a patronising attitude from a higher status older male to a lower status one. (For anyone that's interested, the specific characters are Uchiha Fugaku and Umino Iruka from Naruto.) The vibe I'm going for is master to servant, I think, with an overlay of superiority and disdain on behalf of the speaker. I'm pretty sure that -kun is the way to go, but should that be attached to the first name or the surname? The first name feels too familiar, as though the higher status male is claiming the lower as kin. And yet using the surname suggests a level of respect that isn't really present either. Using none would be rude, but his title (sensei) too respectful.

If anyone has some insights into this quandary, I'd be truly grateful.

Search terms tried... japanese honorific kun surname "first name"