Vrook. He's the de facto leader of the Jedi Order in Vandar's absence, and though I hate to even hint at gameplay experience... I mean... Vrook was a damn pain in the ass in game.
Not to mention the mighty Kavar and Zez-jai Ell obviously were swayed by his wisdom, and he was the only one to recover from Kreia's initial barrage.
Vrook should be able to win this.
And actually Bandon did defeat council members, or rather ex-council members.
The Disciple talks about one that left to join Revan and survived until after Revan returned. Bandon was more powerful then that guy apparantly, so he is more powerful then a council member and probably defeated a council member. What does this mean? Absolutely nothing council members can still suck. But Glentract was right when he said that.