it’s a bit complicated because ~*comics*~ but i’ll try to explain
sue originally lost their second baby, or so they thought. franklin with his nearly limitless power actually transferred her soul(i suppose?) safely into another reality where she grew up happily…. and in this reality sue was married to doom and he was her father.
this valeria von doom got stuck in 616 for a while.
and it was kind of hilarious
anyway, she eventually had to go home, but franklin wanted a sister like her so bad he made sue pregnant again. there’s no way to say that without it sounding very wrong but that’s what happened.
when it was time for sue to have the baby reed was captured by supervillains and unavailable, so johnny reached out to the only person he could think of who’d be able to help them(there was some very serious complications, which is what killed the baby the last time and why it couldn’t be just anyone), and that was doom.
the only thing he wanted in return was to name the child which sue agreed to, so he named her valeria after his childhood sweetheart.
and after this they’ve just had a bond. she’s never feared him, and he adores her for being the shrewd little girl she is. i think she’s a bit more like doom at that age than reed so he understands her a bit better… and encourages some of her bad behavior.
he might not be the best influence.
i feel like he’s simply meant to be part of her life in a significant way no matter what reality, it’s just one of those constants. be it as her father, mentor or godfather, he will be there.