Sasuke plays a big role when it comes to MB at this point. He's essential in most setups as his triple chase is unparalleled at the moment. Guy is also extremely good as he's lightning and boosts Attack and Crit, so that along with Lightning's element boost and Sasuke's boost with Kirin is destruction. Then for the last spot I use Hinata or Tenten as they're both good attack wise and chase wise.