My first reaction was Shaxx. However he is a neglected character. Despite his lore describing him as ranking among the most powerful combatants he never showed up anywhere. He makes as much impact on the story as Rahool. Hell, even Hawthorne contributed more to the story. Drifter had a lot of story involvement and is a way more complex character. Bottom line I am visiting Shaxx more than Drifter but the latter gets my vote.