Identifying an anime about a boy trying to learn magic with their school teacher

Question

I saw an anime a few months ago, 1 episode then had to stop, and can't seem to remember the name now...

The first episode was about a boy in a village with his friends they were trying to learn magic and they had this (female) teacher at school (who was living with the main character) that helped and/or motivated them. At the very end of the episode they came across a man who was somehow a demon and was after their teacher who was hiding from the outside world.

Not sure what happens in between but he manages to injures his friends and the boy and captures their teacher and almost kills her when she (the teacher) asks the boy (who is the main character) to drink her blood to awaken a great power in him. He does and destroys the demon.... not to forget there's a high tower in it that later the teacher and main character go on a journey to reach its peak

Answer 1

This sounds like UQ Holder

In the decade since the world became aware of the existence of magic, the world has undergone massive upheaval. However, a boy named Touta lives in seclusion in a rural town far removed from these changes. His ordinary life is highlighted by his magic-using female teacher and his supportive friends. When his tranquil daily life is disrupted, he embarks on a unique adventure.