I am looking for a manga where the MC is sent 1000 years or so into the future to stop a disaster from happening. The first thing he does when he awakens is to retrieve his master's wand from some ruins. There, he meets a young girl who accuses him of stealing the "holy sword" from her after she had to beat the dungeon to get it. They get attacked, and he kills the monster. After that, he joins a school for holy sword users as a mage. The principal looks like his old female master, and after the duels to join the school, he challenges her to fight, but she refuses and tells him he needs to qualify himself. Also his special magic is to cut anything, even space and time.
It's not ...
- Seiken Gakuin no Makentsukai (or)
- Nana Seiken to Maken no Hime (or)
- Jujutsu Kaisen
... although it's very similar to the first two.