AT 50, you *can* use it as a constant (but very small) damage over time component in long fights.

To get anything out of it, you must

1) have built up a substantial threat lead over everybody else because it's terrible for threat generation
2) You will be doing a good chunk less DPS in order to spam this because it is A) our weakest combo and B) no storm's eye (unless you want to cut the healing in half)
3) You need forced breaks from DPS as part of the fight so you don't run out of TP (why on earth does it cost 90TP?!)

Just be warned, it is not very substantial by any stretch of the imagination, so don't expect to really notice it doing much of anything. But I suppose when you're doing everything to stay alive, every little bit can help.