I find it horrifyingly underwhelming for our lvl 60 milestone (currently capstone) ability, but it has its uses. I kinda wish other abilities in our kit were more like it relative to Dark Arts, where it isn't a buff, it's a function change. Think it would've made our overall kit more interesting. (assuming said functions were worth the MP cost of DA, ofc). I also kinda wish that it gave more MP than Syphon, then using DA on it would feel like a more meaningful choice. As it is, I generally don't need it for MP regen I'm usually in a good place MP wise when it comes off CD so damage all the way.