The weakness is you must be close and it's a one time thing. All the hunters super are used repeatedly before running out. The warlocks have two that are used over time and one that is a single instance (nova bomb) but it has range. Furthermore having landfall on a lightning warlock works the same way as the Titan smash but with slightly smaller radius, then they get to keep on killing. As to how to shut it down I'm almost exclusively a Titan and believe me shotguns shut it down all the time. They tend to use it on large groups of individuals, so you have a large group (3-4) all focusing fire it is over quickly.