Ummm...why iron duke? Run through the game 2 times (doing all the side quests bothe times through for perfect endings) and just smack the crap out of everything. The second time thorough you should be able to reach level 99 if you know what youre doing =/ But then again, I like using beserker and Dark Knights >,>; Especially since I can just go kamikaze with one of the characters with Break Damage limit and do over 60k sometimes =D