In Hawk Moth's lair...
"Whoever thought that someone like her could be useful in negative emotions after regaining her humanity as a vampire," the large circular window opens as sign for him to make his move to create a supervillain. "Oh, this should be interesting."
He extends his hand and a single white butterfly lands on it, and he covers it with his other hand, filling it with dark energy. The process transforms it into an akuma.
"Go, my evil one, and akumatize her."
The akuma flies away from his lair and went for Elena, causing a moth-shaped emblem to appear on her face.
"So, feeling any regrets from what you've done when your humanity was turned off?" Hawk Moth spoke through her head.
"Yes, I feel... everything," was her response. A moth-shaped emblem then appeared on her face.
"Lilith, I'm Hawk Moth. I have given you the power to make things right now that you have turned on your humanity once again."
"Even making amends with Caroline?"
"Yes, even making amends with your vampire BFF."
"And that would make me feel better."
"Yes, it will, but in return, you must do something for me."
"Bring you the Miraculous from Ladybug and Cat Noir. I know!"
With her agreeing to the deal, black and purple smoke covers Elena from head to toe. Once it clears out, her appearance changed. Her hair is now black, has pale skin, and wears a goth-like outfit.
"What a smart girl you are. First, make amends to what you've done, then bring me the Miraculous. Deal?" Hawk Moth stated their deal.
"It's a deal, Hawk Moth," Lilith agreed as she leaves to do what she needs to do.