Fate is the third mercenary working under Chigusa Amagasaki, though he's introduced as a recent arrival from the Istanbul Magic Association—a cover story for his actual hiring by Chigusa herself. Most people call him "Newcomer."
He's genuinely formidable: skilled in both Western and Eastern magic, a martial artist whose fighting style reminds Negi of Chinese techniques, and frankly more powerful and experienced than Negi is at that point. His specialties lean toward water magic and petrification spells, but he's equally comfortable with Eastern practices like summoning demons via ofuda.
Fate's the one responsible for the near-catastrophe at the Kansai Magic Association headquarters—he almost petrified everyone there. He's also the one who actually managed to kidnap Konoka after Chigusa's earlier attempts failed. There's some question about whether "Fate" is even his real name; both Eishun and Professor Akashi's findings suggest it probably isn't.
After his demon god ally gets defeated by Evangeline, Fate vanishes from the story entirely.
Content compiled by AnimeList.moe from publicly available sources.