Walk over to Elizabeth and embrace her

"Of course you did," you tell her as you walk towards her. "I miss you."

"I had our parents killed for separating us," she says.

"No surprise there," you respond.

You wrap your arms around your long-lost sister. She responds by wrapping her own around you.

"I have an idea that's either brilliant or crazy," Elizabeth says, breaking the embrace.

"Go for it," you giggle.

Elizabeth takes your arm with the scar on your wrist and places her scar next to it.

You are buffeted by massive waves of energy flowing both out of you and into you, and judging by Elizabeth's reaction, she is as well.

Suddenly, the flow stops. You realize you've lost your holy powers but gained Elizabeth's immortality.

"I've lost my dark powers," Elizabeth replies to your unspoken question. "We are both creatures of shadow now, immortal, half-light and half-dark."

Patricia walks in, with Patty tagging along behind. You and Elizabeth explain the situation and ask her to work with the two of you.

Being a creature of shadow is... different. But at least you reunited with your sister.