I think she’s smarter than some petty sibling feud though. She’s always had larger goals/ambitions from jump. Ruining her brother or causing him to get kicked out or whatever would really serve no purpose unless he was going to get in her way (which It seems he wouldn’t since, well, he loves and cares about her). Her brother seems too weak and loving, so she probably removed him from her plot so he wouldn’t take unnecessary damage. That’s how I took It (づ￣ ³￣)づ
Welllll I don’t believe she was a villainess from the start. We all saw their past and she was just a regular, but really smart girl. She cared for her brother and they were close. It wasn’t until after her father started “teaching” her stuff that her behavior changed.
a sibling competition in Medea's eyes. She wanted the favor of the duke, back she was still younger. They hosted parties for Deki's achievements, but never Medea's, albeit beating him in private. She was always told that anything she did wasn't enough. Or I'm completely wrong and that's what Dekis thought Medea was thinking. Anyway, I'm just saying that Medea's not an angel, and it's not impossible. Not in all case, but children who are raised twisted, get twisted. She was a villainess from the start, just reminding y'all.