With an overshield that can be activated at any time by holding down O. The barrier is terrible for both PvP and pve , it takes too long to deploy and is easily avoidable. Hunter jump for instance is perfect for just hopping over it. I've also seen many just run through it due to the low damage it inflicts.... It really is the most useless excuse for an ability. It adds zero survivability to titan and the other classes can actually survive a lot more thanks to their great selections of exotics and abilities. This is urgent for the class, you have let it rot and die as a class.