Add the 3D characters, in my opinion, could be awesome but what should they do for the characters? Well here's my ideas

Havik: Make him wear more armor. I think he should be a skeliton wearing his someone's skin but have his skull revealed and parts of the skin he's wearing be cut up. He should also have his mace at his side simliar to a sword. As for his personality, have him have a dark sense of humor but still a leader of chaos.

Hotaru: Have him but wearing heavy armor made out a obsidian and gold and have him wearing his helmet but you can see his face through it. He should have his staff type weapon on his back at all times. He should be a no-jokes leader who is willing to sacrifices to win.

These two should have a major rivaly we will take the wars too far but killing people from both realms even if they aren't involed. There should not ever be any sort of agreement and should get in the way of the heroes tasks in the story mode