That’s why Warren-dono can’t use magic.” (Artur)
To be precise, it seems to be the inability to emit the phenomenon of mana materialization externally.
Instead he used his mana to enhance his body and weapons in battle, so to speak he had the ability to be a so-called magic knight. This was the story of the serving Company Commander of the Chivalric Order of the Royal Guards told by Artur-san.
These types of swordsmen and martial artists who fought by using magic to strengthen themselves in battle had a fixed amount of mana. Compared to people who owned almost no mana, they had an overwhelming strength.