MTL - I’m Always the Villain - Chapter 115 Ghosts do the fake Major General 4

Imperial soldier Suldak Helansa joined the infantry regiment of the Grand Duke Newman in Bena province, participated in the Warsaw plane war, and rescued a young man in the forest battle. This qualified young man suffered some injuries. Injured, still a mute, Suldak brought him into the barracks, and what we are telling is the story of this young man of unknown origin…

- Description from novelbuddy

He—an enigmatic and cold-blooded soldier with a mysterious background.
She—a ruthless and bloodthirsty spy.

It has been more than ten years since he was transported to another world. The protagonist Deris Fahrenheit, who has became a magician with special circumstances, was freely enjoying his life in this world. However, a girl appeared before him and asked him to make her his disciple. That girl seems to be a transported person――

It’s a story of him who becomes the girl’s teacher and trains her to achieve her revenge (?) in otherworld.