Eh, I feel like we’re going to see a lot more development from him. In the book they mention him killing Han as a moment that weakens him, and I’m sure we’re going to see him go through a lot of changes.
I think that, like Vader, he thinks he’s lost, but there are people who know there is still good in him. The interesting bit is when Snoke talks about how he could be seduced by the light side, which is an interesting reversal from what we’ve traditionally seen from the series.
He wants to be the badass in black armour like his grandpappy, but I don’t think he’s got it in him. I think he’s just a scared, confused little boy like Rey said.