Beck

Buffyverse
Beck was a half-demon who appeared as a dark-haired Caucasian woman in her early twenties. She possessed the ability to generate fire from her hands. Following the fall of Los Angeles, Beck found herself as a patient at the supernatural rehabilitation clinic, the Mosaic Wellness Center. During her time there, she met a vampire with a soul known as Spike.

Spike had plans to go out to Las Vegas and invited Beck to accompany him, along with the telepathic fish demon, Betta George. Beck was very emotionally unstable at this point, which made the Mosaic staff reluctant to release her. To insure her safety, coordinator Malposo Angra Mazda Ormazd Yazatas Mainyu made Beck wear special gauntlets to control her powers.

Marvel Universe
Beck was a dark-haired man who was an associate of the domestic terrorist known as Mallen. Along with a man named Nilson, Beck and Mallen illegally purchased a dose of the Extremis enhancile, which had been stolen by Aldrich Killian of the FuturePharm company. Beck administered the dose to Mallen who immediately went into convulsions and began vomiting a stream of thick, black fluid. Scared, Beck and his colleague sealed Mallen inside the D.R. Cole Slaughterhouse in Bastrop, Texas.