I quit

[Falar]

But your single target MP regen doesn't rely solely on Blood Price. And as a whole, it's much faster to refill your MP now, especially if you're under Grit.

This is misinformation, there is no "delay" resulting in a DPS loss. What can be a DPS loss is spending too much MP on Blackest Night instead of Dark Arts, but that's without considering the times where TBN is used for mitigation, and that BloodSpiller ignore's the damage penalty.

Since Bloodspiller is on the GCD every use of it delays the use of your resource generating abilities--SS and SE.