They duplicated

The two Scarlet Witches looked at each other in shock. No one should know about this cottage, no one should know she was here. This was a place for her to relax, away from the other heroes that would judge her, and somehow she wasn't alone in this sanctuary. And it was invaded by someone who pretended to be her.

"HOW DARE YOU!" Wanda floated into the air, hands and eyes glowing with red chaos magic. Her double seemed to completely mirror her, even speaking at the same time as her, which only enraged her more.

The two wanted to yell at each other, scream at the top of their lungs, and rip each other to shreds, but before they could do so they dropped to their knees. Their vision blurred, their could barely keep their balance, and their bodies felt as if they were being tugged in two separate directions.

When they came to there weren't two Scarlet Witches. There were four.