Sephiroth’s actual job (occupation) is SOLDIER 1st Class, which is similar to an elite Warrior. And Final Fantasy VII technically doesn’t have a job class system. Based on how you set up your Materia, you can mimic the traditional classes of the past games.
However, many of your characters in Final Fantasy VII do have skills exclusive to them. These skills are directly related to a type of job class.
For example, Yuffie has two occupations: Ninja and Materia Hunter. As a Ninja, Yuffie has high agility and speed stats and carries an oversized Shuriken. “Materia Hunter” is just another term for “thief”. Yuffie’s character and job class is a homage to the first and sixth Final Fantasy games. In the first Final Fantasy, your Thief could upgrade to a Ninja. In the sixth Final Fantasy, Locke Cole’s job class was technically a
thief “Treasure Hunter”.
So Sephiroth’s might actually have these types of abilities. His primary job class would be Samurai. Like Cyan and Auron, Sephiroth is both principled and stoic.
Sephiroth wields a sword called the Masamune, which is the name of a legendary Japanese blacksmith who made it. One those pure in heart could wield one efficiently, and Samurais were trained to hone their hearts and minds through the bushido.
Sephiroth’s Masamune is as long as a Dragoon’s lance. The first battle we see Sephiroth in is against a dragon, which he slays effortlessly.
When Sephiroth kills Aerith, he performs a move called “Hell’s Gate”, in which he leaps into the air and descends upon his victims. Sephiroth uses the move exclusively; it’s a skill particular to him.
In Crisis Core: Final Fantasy VII, Zack can jump made possible through two different Materias (“Jump” and “High Jump”). Maybe Sephiroth, and Cid Highwind, has this particular Materia equipped?