My thing is defender is one of the best if not best subclasses for Titan: PvP or PvE. Not as applicable in rumble but can still be used effectively. It's not as flashy as HoS or FoH but in my opinion is the titan's bread and butter. As support of a class as a support class can be; you literally shield your teammates with your super. Combine that with helm of st. 14 and your team in the bubble is a fortress of solitude. Add a sword and the right build and you will poop orbs all through a strike.