Lucian is completely different from what he was in the prior games. If you remember, he could not bring himself to kill Damian, even with all that he did and tried to keep causalities to a minimum. In OS2 however, Lucian is completely fine with using Deathfog to wipe out the Black Ring and innocent Elves in the area, He goes to the Godwoken academy and slaughters every other Godwoken there so his son, Alexander is the only Godwoken. If you kill Alexander, and talk to him about it, he doesn't even seem to care. I suppose Lucian trying to ride the world of Source, thus killing The Void, God King, and God's so the races can live without the threat of them can be considered noble, but on the whole he seems like a complete arsehole now.
The big problem with this is Larian went too far with the jerkass part i understand they wanted to make Lucian more grey but they apparently went too far. Would be better if he could succeed and you see him break down thats its finally over or something like that.