Depending on how Mob turns out as an adult, I think in general he'd figure out the whole adult-ing thing well enough to be a good dad. Probably not a strict enough one, though, his partner would have to play enforcement a bit more than he would even if Mob would work very hard to instill good moral lessons in his kid the way Reigen did for him.
then he might dryly joke about taking money from their allowance for bending spoons, if they were an esper too. GOSH. If they were an esper he'd be very attentive to the growth of their personal identity.
if he were MORE of a dad I think he'd probably be the guy to work a bit harder to get his kid the advantages he needs in life. He'd also be pretty freeform I think, Reigen kid would get in trouble a lot.
I'm so into mp100 but opm was just a few months ago...
Mumen Rider sort of ended up as my main, and he would be a surprisingly unreliable dad I think - always gone for the sake of hero work and living in a dangerous lifestyle. His partner would have to pick up the slack.
Genos would probably drastically change his personal life priorities if he had a family to take care of, tbh. Self preservation would dramatically become more important, as well as the need to monitor his son/daughter... it'd be good for Genos, but the kid would have a nearly-literal helicopter parent
Saitama needs help if he becomes a dad but he'd probably generally be the best at just being around for the sake of parenting. Sometimes being casual and winging it just works out better for raising kids, given that the kid isn't a total brat. Also there's no safer kid in that entire world than Saitama's kid...
Seimei (from when I was RPing Loveless) should never breed, what a horrible thought
Yuuri (Kyo Kara Maoh) was another character I played a lot of! And he actually already is a dad!
He adopted a girl named Greta who was forced through certain circumstances to try and assassinate him (since he's the demon king) but he adopted her. He takes good care of her and spoils her rotten and surrounds her with a loving happy family (Wolfram, the rest of the brothers, the staff that's all softened up and happy from Yuuri's leadership, etc)
Moro was also a main for a long time and she's also already a mom. She's pretty good at it for being an old ass wolf god. Loves her ugly adopted human daughter just as much as her natural born sons. 10/10 would throw my baby at her feet for her to raise too
most of my other past mains are "they probably could but I can't picture it" or "pls never breed"
i always get a kick out of characters who can be described as "not allowed to breed"
i think because manifestations of that idea irl are always for horrifying reasons but in fiction it can be something hilarious like "punches gods for fun, would probably throw a baby at cthulhu, Not Allowed"
it's the lovable trainwreck principle
would i want to know this person irl? no. are they fun to witness as a character? fuck yes

please never let this virginal murderous psychopath reproduce (not that he would anyway bc this sick fuck)
I like some seriously horrible characters lmfao I LIKE THAT I CAN POINT AT THAT HUMAN CHARACTER AND GO "DON'T BREED" BUT THEN POINT TO ANGRY WOLF GOD AND GO "THAT ONE, THAT KILLER CAN HAVE OFFSPRING"
i don't actually know the character in question this just sparked the thought
which had been floating around, because lmao this meme

this girl is a mix of "literally how" and "you would leave it in a dumpster once you got bored wouldn't you"
(the literally how coming from the fact that she's an AI program not that she's a furry)

RIGHT THIS GIRL is already a mom
mom to all creation, came back from the dead to clean up the mess then wandered off and sent her newest son to go clean things back up once they got messy again
i.e. she assigns chores, mom is busy, etc