Emrakul- Process of transformation

She sank her blade deep into the thing—right above a foot still resting in a stirrup, she realized with a jolt of revulsion—and the volume of its cry increased. Several other cathars had come to her aid, and they swung heavier swords and axes until the horror lay twitching at their feet.

And Dennias, who a year ago had been a naive trainee at the Elgaud Grounds, knelt on the ground clutching his head as though he were trying to keep something inside from bursting out. His mouth gaped open in a silent scream and his wide eyes stared at nothing. His friend Mathan fell to one knee beside him, putting an arm around his shoulder and murmuring empty words meant to comfort. Thalia turned away.

Then Mathan screamed.

Thalia whirled around and saw Mathan scrambling back, his face white as a gryff. Dennias hadn't moved, but long tendrils, like magenta ribbons, protruded from between the fingers of one hand. Protruded from out of his ear.

His face went pale, and he looked like he was going to vomit. Shaking her head sadly, Thalia took a few steps toward him. She knew what was coming.

He doubled over as if to empty his stomach, but more of the tendrils came out of his mouth instead. Something large squirmed beneath his armor at his sides, too.

He was lost.

SAINT TRAFT AND THE FLIGHT OF NIGHTMARES