Well, she is a hybrid of human and monster, with the monster bit being sourced from what was left of Asriel/Chara after they went to the surface. So, she'd probably just abosrb souls, using them to augment her powers like a monster would.
Alpha
That cold, dead, murderous glare continued to bore into the twisted abomination in front of her. More specifically, into the projection of Nocturne. Whether by the collar's beeping, or just a good sense of what was around him (she figured the former), he seemed to feel it bear down on...
Alpha
More people started to wake up. What seemed like another test subject (he had that look in his eyes, that kind of look she was so familiar with in her younger years), a masochistic....ninja? Or was she sadistic? Alpha couldn't quite tell, and thought she might've even been both. Following...
Alpha
Alpha didn't quite remember how she got here. In the few glimpses of consciousness she had to herself, the Boss Monster would mostly still be attempting to reconcile her battered body and new locale with her former situation. The few flashes of clarity she gleaned from the moment would be...
Name: Alexandria "Alpha" D'Angelo
Age: 20
Motivation: Wants to see whoever put her here dead, preferably by her own hand.
Fatal Trigger(s): Being threatened with experimentation, losing her journal (with all of its secrets)
World Origin: Undertale/OC (bite me)
Powers/Abilities...
Name: Alexandria "Alpha" D'Angelo
Age: 20
Motivation: Wants to see whoever put her here dead, preferably by her own hand.
Fatal Trigger(s): Being threatened with experimentation, losing her journal (with all of its secrets)
World Origin: Undertale/OC (bite me)
Powers/Abilities...
I'll have to watch another playthrough of 358/2 days tho, because KH chars are hard to play because nobody know's what's going on in Nomura's wild ride