am i the only one who remembers derek tell erica to back off form scott because he had someone else “planned” for her ?
No, Derek was telling Erica to back off of HIM, because he had someone else ~planned for her. Then he sent her after Scott. That didn’t work out. This episode he told her to get on the good side of one of the boys. When asked which one, Derek said “either.”
When Erica saw Stiles chasing after Lydia, she saw an opening and went for it. It’s possible she never did have a crush on him, and was just manipulating him. That said, I think her Batman comment was sincere, just based on the timing.