Looking for a manga

So I once started reading this manga about a young man who was raised to be an assassin(?) and he enrolls in a school where he meets two young women. Iirc, one had red hair, the other blue(?). He trains them in magic, but also it turns out he was the one who killed the blue haired woman’s mother. There was also an odd method he used to efficiently teach the red haired woman. I can’t seem to remember the name. Pls comment if you read something similar. Thx!