Ashiok Warlock Trigger
If Ashiok has achieved the final level of Warlock, every time a Nightmare triggers, an additional 1 drain occurs. This occurs no matter whether the card drawn/milled is a creature or not. For example if a card is drawn/milled for a Nightmare x4, the opponent is drained for 5, x1 for 2, etc. Appears to be a bug or improper wording on the Warlock spell.
Bueszien#60745 shared this idea