Nightmare is very flexible for a 3-cost card. In some fights it can target your best scaling power, to overwhelm the enemies over a longer fight, or even a card draw resource in order to massively improve your deck's ability to cycle quickly, while in shorter fights it might target Adrenaline or even a Backstab just to get lots of output from it as quickly as possible. Good with a way to cheat energy so you can play it more easily, like Bullet Time.
