Weapon: - MASAMUNE; Sephiroth's weapon of choice. An oversized version of the more practical Nodachi; Masamune stands at an impressive seven feet long, and, despite its massive size, is easily handled by the 1st class SOLDIER. Both the tsuba and tsuka of the weapon have been colored black, and can generally be spotted nearing his left shoulder whenever his position in battle is taken. Even with its great measurements the sword can still be readied with either one or two hands.
Abilities: - Superhuman; Sephiroth has exhibited not only superhuman feats of strength, but speed, reflexes, endurance and dexterity. A rather large range of these playing an important role in his swordsmanship as he is able to cut through concrete, and even solid metal, with relative ease. It should be noted that he also possesses the ability to both levitate, take flight, and even teleport in some instances.
- Swordsman; The trademark of this SOLDIER's fighting ability, and the thing he's rarely seen without. Sephiroth's skill in this area is without question and allows him to wield his treasured Masamune with no problem, matching others with shorter, more capable weapons without hindering his ability. He has been known to form waves of energy by swinging his blade, and his superhuman traits allow him to strike multiple times in a mere instant.
- Magic; With his little dip in the lifestream, Sephiroth took on the ability to make use of magic without the aid of materia. This shown in abilities such as his shadow flare.
- Sephiroth's Wing; The SOLDIER boasts a single black wing that protrudes from his right shoulder, though, it doesn't make a constant appearance.
Personality: There is something to be said about this SOLDIER, or any SOLDIER, really. Sephiroth is calm to an unnerving degree, and one could go as far as to call him stoic in many regards. It comes with the territory. If you want a job done you hire the person with the right mindset, and that's one that Sephiroth possesses, and proves, time and time again. He's as cool and collected as one can get without being a complete husk.
That isn't to say that Sephiroth has settled down as a complete outcast; he's very specific about the few he keeps close, rather, and it takes a bit of doing to get to a point in which you can be considered such. He had his mates some time ago; the ones that managed to work their way into his life, and to them, he remains loyal. You might even say that the apex professional was friendly if all of the elements lined up. It's rare, but not entirely out of the question.
It could be said that he's a bit narcissistic, over confident, arrogant, whatever it is you'd like to call him; it acts as a bit of a window into the mind of an otherwise dispassionate individual. If lucky, you might get to experience his rather poor sense of humor; the second of a few traits that lend a hand into the cheerier sections of Sephiroth's mind.
With several blows crippling his mental state, Sephiroth has managed to only become colder. He's taken on somewhat of a sadistic streak, and seems to take great joy in the harming of others. He has become a malevolent force, and as shown with many of his encounters involving those that might stand against him, shows little to no regret for his actions.
History: After his birth, Shinra raised Sephiroth to be a super soldier. They told him nothing of his mother except that her name was "Jenova," and that she died during childbirth. Sephiroth proves to be incredibly strong, gaining worldwide fame for his exploits such as his role in Shinra's victory against Wutai in 0000. He was aware since childhood that he was different from the other children, although he did not know the exact reasons why he was different until several years later.
President Shinra comes to rely on Sephiroth, calling him in whenever the situation personally threatens the President's life, like during the first AVALANCHE attack on Junon on February 30, 0001. Sephiroth engages the AVALANCHE leader, Elfé, but she blocks his strikes, impressing him. While the two are fighting, Elfé questions why Sephiroth is fighting. She asks whether he ever wants to "fight for a reason," which seems to have a profound effect on him. The results of Sephiroth choosing to fight for a reason would one day threaten the entire Planet's existence. He is later sent in on June 18, 0002, to "rescue" Professor Hojo who had almost defected with the AVALANCHE forces attacking the Shinra Headquarters.
In SOLDIER, Sephiroth has two friends, Angeal Hewley and Genesis Rhapsodos. Though the three are rival SOLDIERs First Class, they see each other as close friends. When Genesis and Sephiroth duel in the virtual reality Junon, Sephiroth seems to be the strongest, but the fight ends inconclusively. Angeal stops the fight before either hurt each other too badly, although the small wound Genesis takes does not heal. Sephiroth offers his blood as a transfusion, but is told his blood is not compatible. Genesis defects from Shinra, making Sephiroth uneasy about his missions against him, and when ordered to go to Banora to track him down, Sephiroth refuses the mission. Just before his final mission, Sephiroth hints he may leave Shinra altogether.
In what would become his final mission, Sephiroth is ordered to inspect the Mako Reactor outside the town of Nibelheim on September 22, 0002. He enters with a small entourage, consisting of one other member of SOLDIER and a few Shinra MPs. Among this group is SOLDIER 1st Class member Zack Fair and his friend, a seventeen-year-old Shinra trooper named Cloud Strife. At the reactor, Sephiroth finds several pod-like chambers containing monstrous creatures, apparently former humans, mutated by exposure to Mako. Deeper inside, he finds a larger chamber labeled "JENOVA" containing a strange feminine-looking creature. When Zack suggests a connection between SOLDIER and the creatures in the tanks, Sephiroth flies into a rage, deeply horrified that the reason he was "different" and "special" from everyone else was because he was created from the remains of a monster.
Deeply disturbed by the fact the creature had the same name as his "mother," and by the idea he might have been created in an experiment similar to the one that created the monsters in the pods, Sephiroth makes his way to the manor that had been occupied by Shinra researchers, and begins reading the research notes in the basement library. As a result of what he learns, Sephiroth becomes enraged and psychotic. Based on the Shinra reports, he comes to believe Jenova was a Cetra, and therefore he as Jenova's "son" is the last Cetra survivor. He also believes the human race had betrayed the Cetra 2,000 years in the past, leaving them alone to defend the Planet from a calamity it had faced, and resolves to take vengeance for his "ancestors."
On October 1st, Sephiroth proceeds to destroy Nibelheim, setting the town on fire and killing many of the townspeople, before returning to the reactor to claim Jenova's remains. He is pursued by Tifa's father, Tifa, Zack, and Cloud. At the reactor, Tifa takes up Sephiroth's Masamune from her father's corpse and attacks him, but he disarms her and cuts her down. Shortly after entering Jenova's chamber, Zack arrives and attacks him. Zack is defeated and tossed out of the chamber. Cloud enters the reactor and picks up Zack's Buster Sword, rushing after Sephiroth. Caught off-guard, Sephiroth is impaled from behind through the abdomen and collapses.
Due to Sephiroth's enhanced anatomy he survives Cloud's assault, though wounded greatly. As Cloud leaves him to tend to Tifa, Sephiroth slices off Jenova's head and stumbles from the room. Cloud attacks him again, but Sephiroth stabs him with the Masamune. Cloud summons unknown strength and uses the sword as a lever, hurling Sephiroth into a pool of Mako below the reactor. Sephiroth vanishes with Jenova's head still in his grasp, apparently falling to his death. Following the Nibelheim Incident, Shinra seals the records on Sephiroth, declaring him killed in action, and rebuilds Nibelheim in order to cover the incident up, populating it with Shinra employees paid to act as the town's citizens.
In actuality Sephiroth fell into the Lifestream, his willpower too great to allow himself to be consumed. Over the next several years Sephiroth travels the Lifestream, increasing in power and knowledge, and eventually the fragments of his body congregate at the Northern Cave inside the North Crater, joining to recreate Sephiroth's physical form in a cocoon of Mako. His powers and desires enhanced, Sephiroth's goal now is to merge with the Lifestream and seize control of it to become a god.
Though his physical body is encased in Mako, Sephiroth is now able to control Jenova's cells as an extension of his body and thus act on his plans through her. Hojo meanwhile injects Zack, Cloud and the survivors of Nibelheim, except for Tifa who was saved by Zangan before Shinra found her, with Sephiroth's cells, turning them into Sephiroth Clones. Hojo believed the Jenova cells inside Sephiroth would call for a "reunion" of those who shared her cells, and wished to see his theory put to the test.
Approximately five years after his supposed death, in December 0007, Sephiroth enacts his plan and puts out the call for the reunion to call the Sephiroth Clones to travel to the North Cave. Jenova's remains, which had been moved to Shinra Headquarters in Midgar, shapeshift into Sephiroth's form and break out of containment. Jenova/Sephiroth releases Cloud and the members of AVALANCHE, who were being held prisoner, and kills President Shinra after declaring Shinra should never acquire the Promised Land.
He also appears some time later in Nibelheim, where he again mentions the Reunion. At the Temple of the Ancients Sephiroth reveals the full extent of his plans - the Planet relies on the Lifestream to heal itself when wounded, and the North Crater where the Lifestream is abundant is where Jenova fell two thousand years ago. Using the Black Materia, Sephiroth plans to call the Ultimate Destructive Magic - Meteor. The impact caused by Meteor will heavily injure the Planet, and Sephiroth will place himself at the center of its impact zone as the Lifestream emerges to heal the Planet's wound. Thus Sephiroth will merge with the Lifestream, becoming a god ruling over the Planet.
Cloud succeeds in acquiring the Black Materia, but Sephiroth exerts his influence over Jenova's cells and takes control of Cloud, who hands the Materia over to Jenova. At this time, Aeris Gainsborough, the true last survivor of the Cetra, tries to use the White Materia to summon Holy, the only power able to counter Meteor. During her attempt to call forth the Ultimate White Magic, Sephiroth (or rather, Jenova transformed into his image) impales her with his sword, killing her. Though Aeris had successfully called Holy, Sephiroth holds it back within the Planet with his will as augmented by Jenova's power.
At the crater, Cloud kills Jenova in Sephiroth's form and reclaims the Black Materia, this time giving it to a party member to keep it safe. Cloud and Tifa continue deeper into the crater and an illusion of Nibelheim's destruction that Sephiroth conjured in order to break Cloud by revealing that his mind pieced together the events of him there instead of Zack. Furthermore, Sephiroth breaks Cloud by deceiving him into thinking that he is nothing more than a cluster of Jenova cells that assumed the identity of a boy named "Cloud."
Sephiroth's manipulations and lies take their toll, and shatter Cloud's fragile mind. Meanwhile, Sephiroth projects an illusion of Tifa to appear before the party members left behind to bring the Black Materia to Cloud. Once Cloud takes back the Black Materia, Sephiroth reveals his true body as he receives the stone and uses it to summon the Meteor. The crater collapses, and Cloud's allies are forced to flee with Rufus Shinra. The Planet unleashes the Weapons from their sleep and Sephiroth erects an energy barrier over the crater to keep them from detecting him.
With the Weapons wreaking havoc and keeping his enemies from rallying against him, Sephiroth begins shapeshifting his body into a form befitting a god, awaiting Meteor's arrival. Cloud eventually recovers and the party receives unlikely assistance from Shinra. In later January 0008, they fire the Mako cannon, known as the Sister Ray, at the North Crater, piercing Sephiroth's barrier and allowing Cloud and his allies to enter the crater and find Sephiroth.
Emerging from his larval Bizarro∙Sephiroth form upon defeat, Sephiroth as the angelic Safer∙Sephiroth, a god-like being with seven wings and great power. Cloud and his allies destroy Sephiroth, but his mind endures as Cloud and his allies begin to escape the crater. Pulling Cloud into a metaphysical final battle, Sephiroth attempts to take control of Cloud, but Cloud's mental defenses have grown, and he defeats Sephiroth. Battered and bloody, Sephiroth dissolves into the Lifestream, seemingly destroyed forever.
During the events in 0009, Sephiroth is still dead but remains an active force terrorizing the Planet. Geostigma has spread throughout the world, afflicting many with extreme fatigue and open skin sores. The plague is revealed to be caused by Jenova's remaining consciousness in the Lifestream, and primarily affects children due to their weaker immune systems. The disease has also affected Cloud, who experiences visions of Sephiroth numerous times.
Cloud finds himself confronted by a trio of silver-haired men who are physical manifestations of Sephiroth's will. The three, Kadaj, Loz and Yazoo, believe they are guided by their "mother" Jenova, but rather it is Sephiroth himself who forces their actions. The three seek Jenova's cells in order to be reunited with her, unaware of Sephiroth's ultimate plan to recreate a true body for himself using Jenova's last remnants.
Kadaj absorbs Jenova's cells, and Sephiroth exerts his power over Jenova to shapeshift Kadaj's body into his own visage, restoring him to life once again. Sephiroth faces Cloud and reveals his new plan - to taint the Lifestream with those dead of Geostigma to the point he is able to control it, and use the Planet as a vessel to travel space and find a new Planet for him to rule.
Sephiroth and Cloud fight in the ruins of Midgar, and Sephiroth eventually gains the upper hand. Taunting Cloud before dealing the final blow, Cloud is reinvigorated by memories of his friends and family and destroys Sephiroth, utilizing his Fusion Swords to assault him from all directions. Weakened, Sephiroth announces that he will never be a memory. His black wing folds around him and fades away in a flurry of dark feathers, leaving a weakened Kadaj to die and fade into the Lifestream.
Pulled from the lifestream; the fallen angel approaches the new world with what remains of his plan. His eyes opened to a new scene, a true form of being, one that had eluded him for so long, he awoke to find this new land.
( Credit to FF Wiki )