Dark Passenger eats mana.

If mana isnt an issue---sure go nuts! Its OGCD

In most other cases, newp. Better to use it on enhancing another ability (another dark arts for instance). On the reverse, if its 2+ enemies, then id instead use it even at its base potency over a dark arted ability (100 potency * 2 targets vs say, soul eater going from 280 to 400 on one).