Poe hands down. The speed of his taunt, chance to expose. That being said I would never waste a spot in arena for Chewie or Poe. There damage is highly reduced from there given stats on the character screen. Idk why I guess for balance. People play to defensive in arena with multiple healers, taunting tanks high hp only characters. Get you a good synergized AOE team and you can be competitive in the higher top 10 ranks without spending a dime right now because people are still clinging to healer teams. Synergized DPS are a beautiful thing when it comes together. Win some, lose some but mostly win.