His interactions, rather lack of, with Nanna in FE5 are especially striking considering the parallel we’ve been exposed to with Eyvel and her daughter. 

But then Eyvel is the best Jugdral parent without contest so

I mean, when they meet each other, there is no exclamation mark at the obvious “you’re alright thank goodness” when there is one with Leif. Plus... the Raquesis mention - if Nanna died Finn’s only concern would be how to say it to Raquesis “well sorry your daughter kind of died”, no personal guilt nor sadness? Is Nanna only a “souvenir” Raquesis left him? 

Nanna’s eloquent “Father...” and Finn’s “is there something wrong” are really telling a story here, maybe Nanna wanted to lash out against him at how he was more worried about Raquesis than his own daughter’s safety...

(I guess FE5!Nanna has really complex feelings about her mom and again living with Eyvel might have taught her what a real mom was and how Raquesis was a bad one per her own POV)

Besides, I think he was more a retainer like figure compared to a fatherly one to Leif - even if Leif doesn’t think so - I can’t shake the idea that Finn cares about Leif because he is Quan’s son and Lenster’s heir, and not because he is that kid he lived with for a decade. I think it is quite important that Finn doesn’t get to scold/argue with Leif like Dorias/August do, he had no lines in the Alster fiasco. Finn will support Leif but never scold him - just like Leif noted himself when talking to Eyvel. A parent scolds/corrects his child when he makes mistakes, Finn doesn’t. In this way, I read him more as a loyal retainer/knight than a Father figure.

I honestly wonder how his relationship with his kids changed (or didn’t) when they lived with Eyvel and Mareeta.