This is mainly a personal headcanon of mine, but I feel like Donte and Nero would be friends. They just treat one another like weird, distant cousins, but still, I feel like they could get along. Maybe Nero would have to get Donte to quit doing some things (because Nero is a sweetie pie and also just like. Genuinely a Good Dude), but I feel like it'd help Donte more than hurt him, y'know?
It'd also help that Donte could actually trust Nero not to manipulate him or betray him (I'm looking at you, Virgil), because like. I feel like Donte kinda needs that, after what Virgil did, y'know? The fact that Nero is (sorta, kinda) family also helps, too.
I'm guessing this is like Reboot Nero if he existed
Honestly, it's pretty difficult for me to tell what Donte would be like by the time he and Nero meet.
Like, if we go by Main line Nero and Dante, they meet when Nero is already an adult - in the reboot, I'd feel like they'd meet way earlier.
Going by the possibility that Kat is Neros mother, Nero would probably even grow up with Donte. Just maybe, in that case, Donte would pose as a father figure/at least be the cool uncle that Nero just sees as his dad because he fills in the role. Honestly, I think in that case, Kat and Donte would raise Nero together.
If Kat wasn't the mother, I feel like they'd probably meet randomly at first. Probably during Neros teens, where he might get more into Dontes' bubble of life (or more his previous bubble) and Donte would just get like... fucking run over by the resemblance of Nero to Virgil. He'd probably observe Nero for a while, just like in the Main line. In that case, your headcanon definitely fits. They'd be REALLY awkward around each other, to a point where it'd be kinda funny
