Nah, Arrow Rain (aka Volley) is no good for strong enemies.
The Arrow Rain is good for travel, if you need to kill weak mobs really fast. And it is also good for Arez Quest. There were quitte a lot of weak mobs.

Dracula (bats of Goddess Skill Quest) is very strong and really hard to kill. You can better use Hot Fire and powerful magical or physical skill attack. Other elements than fire are very busy with assistant skills and cure SP with foods.