Satan Girl.

Air lashes around you from the shockwave caused by the fist slamming into your hand. The power house behind it was the spitting image of Supergirl. Well, mostly. Aside from being dry, her body certain looks identical, but rather than the bright blues, reds and yellows, this Supergir is wearing black with silver trim and S. She also is wearing a lot less. Her top stops short just under her breasts, giving a nice big swathe of midriff, and her skirt is shorter with no sign of any modesty shorts underneath.

"My Supergirl could learn a bit from you," you smile, before dishing out your own counter blow. She isn't ready for the hit and is sent spinning back through the air, crashing into the cavern wall.

"That's Satan Girl!" Supergirl calls in surprise as she floats beside you.

"You have an evil doppleganger called 'Satan Girl'?"

"It's... a weird story. She's basically my 'shadow' brought to life by red kryptonite. Only, she can't last in the real world on her own... but the red kryptonite she used to try and drain me to stay shouldn't work on me anymore..."

"That's true..." Satan Girl smiled as she stood up, her durability letting her shake off the hit. "But then I found out there was another Supergirl I could steal the light I needed to live from."

You look back at Power Girl, dangling in the chains that she should be able to snap so easily. In your astral vision her body is dim, mortal. You don't know what this means for her life, but clearly, you had better settle things quickly.

"How're we doing this?" Supergirl asks you, deffering to your judgement on how to handle the situation.