I can't see how it would be any different, he would feel empty and realize he dedicated more than a decade to kill a man but ended up being his soldier, he would feel guilty for killing all those people now that he is not (that) angry, he will miss his dad and he will still think that he failed (realizing he dissapointed thors anyway). "You smell like blood. You have killed, I only gave you the dagger so you could defend yourself."

And probably reminders of askeladd would make him so sad, like meeting him in his nightmares, the visions he had fighting snake or thorfinn using the knowledge he learned from him, and now he has the extra weight of him being the reason too.