Fantasy manga with a male lead mage/sage that has a female companion combat maid

Question

Fantasy manga with a male lead (ML) mage/sage that has a female companion combat maid that was either vampire/succubus half human?

I believe that it was mainly black and white. I don't remember too much about the main character, but the companion has been with the ML since birth. The ML's mom died early and she took care of him and raised him as his maid. During that time, due to the companion's nature (I forgot if it was vampiric or succubic), she became overly infatuated with him even as a child. Later, we find out she's actually skilled in combat and she helps him in battles. As far as I remember, she used dual crescent-shaped blades (I could be wrong). I remember there being quite a few battles with demons hiding out in human society.

Answer 1

This is likely Boundary Labyrinth and Magician of Alien World.

When Theodore was dropped into a waterway by his half-brother, he suddenly recalled the memory of his past life. He had been a Japanese citizen known as Kirishima Kagehisa, placed inside VRMMO character he had made in Break Force Online. ‘Theodore’ is a Combat Mage that Kagehisa played within BFO, and he realized his skills were progressing well even in this other world. Theodore, who had lightly brushed off his half-brother to make his own place in the world, had ventured off to the large labyrinth existing at the Boundary City, Termuilles, to find his own place in the world.

The maid is Grace, a half-vampire combat maid that has worked with the protagonist since he was a child.

She dual wields large axes.