The Titan Striker is a master of counter attacks, as long as you don't waste your Fist of Havoc as a Fist of Panic. Try out Headstrong with Unstoppable, and use it to counter: Bladedancers, Gunslingers, Defender bubbles, Sunsingers. And the sort of toughest one to counter the Nova Bomb. Also that lightning stick grenade is one of the strongest grenades in the Crucible. And if you want to use Shoulder Charge or Juggernaut get the Eternal Warrior. Unstoppable is a must.