My favorite characters from Vesperia is Yuri since he is a dark hero. Though the story behind Duke is also quite interesting as well.
Also, did you get to fight the boss in its secret last form? That was an annoying fight so I ended up doing some cheap shots.
Didn't know it had a secret last form... Will check out about it.
You need to collect all the Fell Arms to do so. It will probably require quite a bit of backtracking and grinding to do so. But the benefit is that you can use the Fell Arms afterwards. They are considered the strongest weapons but the attack is dependent on certain conditions (requires grinding).
If I ever played a NG+ I'll try to collect them all.