To pre-emptively answer your question:
"[Irish mythological hero/demigod Cú Chulainn] is known for his terrifying battle frenzy, or ríastrad (translated by Thomas Kinsella as "warp spasm" and by Ciarán Carson as "torque"), in which he becomes an unrecognisable monster who knows neither friend nor foe."
I.e.: Hulking out.
(Merely here due to Irish mythology? Or also the influence of Marvel Champions?)
from The Táin (Táin Bó Cúailnge) [translation KInsella]: "The first warp-spasm seized Cúchulainn, and made him into a monstrous thing, hideous and shapeless, unheard of. His shanks and his joints, every knuckle and angle and organ from head to foot, shook like a tree in the flood or a reed in the stream. His body made a furious twist inside his skin, so that his feet and shins switched to the rear and his heels and calves switched to the front... On his head the temple-sinews stretched to the nape of his neck, each mighty, immense, measureless knob as big as the head of a month-old child... he sucked one eye so deep into his head that a wild crane couldn't probe it onto his cheek out of the depths of his skull; the other eye fell out along his cheek. His mouth weirdly distorted: his cheek peeled back from his jaws until the gullet appeared, his lungs and his liver flapped in his mouth and throat, his lower jaw struck the upper a lion-killing blow, and fiery flakes large as a ram's fleece reached his mouth from his throat... The hair of his head twisted like the tangle of a red thornbush stuck in a gap; if a royal apple tree with all its kingly fruit were shaken above him, scarce an apple would reach the ground but each would be spiked on a bristle of his hair as it stood up on his scalp with rage."
Eldritch horror indeed.
(Honestly, I'm disappointed we didn't get some flavor text excerpting a translation.)