Only thing I can think of to maybe change it is you get a choice.

You either let it run it's course for lots of damage, or you get the ability to press the lb button again to stop it and land for less damage, the faster you pressed it, the less damage it does.

Other then that, as it is, it's the best zoning tool in the game, even in FL.
Forcing 10 people to guard early, only to get dropped by a black mage ult right after is the kind of plays that win you the game.

It's not always about you getting the kills, it's also about setting them up, and dragoon ult is amazing at it, you get far more value out of one good zoning aoe ult then a machinist killing 1 player out of 23.