Sephiroth is an AI-controlled party member in Final Fantasy VII during the flashback sequence of the Nibelheim Incident. He wields the Masamune and his equipment and Materia cannot be changed. He is programmed to be invincible.
Battle[]
Sephiroth's stats.
Sephiroth is an AI-controlled temporary party member in Cloud Strife's flashback. He cannot take damage in battle and also cannot be healed with restorative spells, and will not lose MP in any scenario due to a special script. He acts of his own accord, and his equipment cannot be removed during the flashback. He has no Limit Break and his Limit meter will not charge since he cannot take damage—if hacks are used to increase the meter, he does not have a Limit command. If the player used him outside of the flashback (not possible in a normal playthrough without hacks/mods/cheats/trainers), Vincent's Limit Breaks appear. Sephiroth is immune to all statuses except those inflicted by Battle Square rolls, but he takes 0 damage when poisoned.
His Materia are mastered Revive, Restore, Earth paired with All, Fire, Ice paired with All, and Lightning paired with All. His weapon has perfect accuracy (255%) and his weapon attacks are always critical. His equipment and Materia are as follows:
| Equipment | Materia | |
|---|---|---|
| Wpn. | Masamune |    
|
| Arm. | Gold Armlet |
|
| Acc. | Tough Ring | |
If there is an enemy within his close range reach, he uses his normal Attack with his weapon. In every other battle scenario (an enemy out of reach or groups of enemies), he attacks with spells (Quake3, Fire3, Ice3, and Bolt3). Sephiroth does not use Restore spells and uses a Fire3 spell only when there is one single enemy out of reach. For groups of enemies, he uses Quake3, Ice3, or Bolt3, except if there is at least one Sonic Speed or any flying enemy or enemy that Earth spells will miss against in the enemy team, which prompts him to not use Quake3. If Cloud falls, Sephiroth sometimes revives him with Life2. Because he does not lose MP (inside and outside of battle in any circumstances), his Revive and Restore spells can be used outside of battle to revive/heal other party members with 0 MP cost.
Sephiroth will win every battle in the flashback regardless of Cloud's status. Twin Brain's Stare Down, as any other status-inflicting changes (except Battle Square rolls), and Earth-elemental damage, always miss against him. His victory pose is to swing the Masamune in front of him twice, flip it over in his hand, and slide it curve-up against his waist so the hilt rests at his side and the blade faces up at an angle behind him.
Stats[]
The player cannot level Sephiroth up in a normal game because he cannot be obtained as a party member legitimately outside of the flashback (and the flashback lacks a post-battle screen, and the player does not gain any spoils). If used as a party member outside of the flashback via cheats, he can gain EXP and level up and gain stats, meaning that he has EXP growth curve and an unknown stat growth mechanism. He starts with 320438 EXP (which, according to his EXP growth curve, is too much for level 50 and should put him on level 51, and when he enters battle and wins, and gains even 0 or more EXP, he automatically levels up to 51 because of that). His current 320438 EXP and 59562 EXP to next level are made-up numbers.
He probably shares his EXP growth with Cloud and his stats growth mechanism is unknown. There are two possibilities: he either uses values outside of normal values used for stats growth by normal characters, or an entirely different mechanism. The same happens with "Young Cloud" who has the fastest leveling curve to level 99. Young Cloud also has unknown stat growth mechanism and most likely the same type of stat growth as Sephiroth but even better.
Stat-increasing sources do not work on Sephiroth, perhaps because he is not a normal party member and not intended to be used outside the flashback, and therefore there is less room for his data and stat increases from sources cannot be stored anywhere (stats increased by sources is different data than normal stats and stats growth).