Ulamog Brood- Keeps fighting until it is drained of all energy

She thrust her mouth into the beating magenta heart of this monstrous Eldrazi and she drank. She drank deep. Clarity blossomed.
…
She drank deeper, deeper. The energy from the large Eldrazi flowed into her, suffused every starved pore in her tightened flesh. The Eldrazi sire had a huge hole in its chest where she had burrowed, but it was still upright, still killing, still marching upon her people. She needed more.
…
She drank in everything, every particle of the Eldrazi energy around her. She obliterated it and consumed it and bathed in it. The empty meat surrounding her exploded, leaving nothing but Drana floating in space observing the massacre below her.


(Memories of Blood)