Naraku_Diabolos on 20 February 2011
No one mentioned Duhallan from Golden Sun: The Lost Age and Golden Sun: Dark Dawn 
Unless your characters were grinded to Lv99 on The Lost Age, there's no way you could beat him. I still can't beat him on there, but I have on Dark Dawn as it's easy to get to Lv99 with all of your characters.
