Dark Depths

The Dark Depths is just beyond the Great Maw in Hollow Bastion. Several cutscenes are shown at the Dark Depths such as Axel confronting Sora and tells him of the Organization XIII's plans with Kingdom Hearts when Saix warps in to try and capture Axel. Once the MCP has been defeated, Sora can find and battle Sephiroth here. You can see the Villain's Vale where Maleficent used to reside from the Dark Depths. In Kingdom Hearts (game), the area where you fight your first Behemoth and seal Hollow Bastion's Keyhole is also called Dark Depths.

Sephiroth's Attacks

 * Flash

Description: the screen darkens, and Sephiroth says "that's enough" before dashing past you. Sora then is hit multiple times. It can be avoided quite easily by using the Reaction Command; otherwise it is virtually impossible to avoid except with deft jumping.


 * Ground Omnislash

Description: Sephiroth charges forward, unleashing several quick damaging slash attacks. These can be avoided simply by keeping your distance, leaping over them, or using Guard. Later in the battle, Sephiroth dashes behind Sora before starting the series of slashes.


 * Aerial Omnislash

Description: Sephiroth only uses this move when Sora is in the air and attacks him multiple times, after which he teleports. Sephiroth often uses this attack three or more times in a row. They can be avoided by using Aerial Dodge and counter-attacking when Sephiroth re-appears.


 * Teleport Slash

Description: Sephiroth teleports behind Sora and attacks, knocking him high into the air. This is usually followed up with Aerial Omnislash. This move is difficult to detect and avoid, but can be blocked with Guard and fast reflexes. Even if Sora is hit, the follow-up Omnislash, as told above, can be countered easily.


 * Shadow Flare

Description: Sephiroth summons several dark orbs around Sora that follow him around briefly before hitting him. They can be deflected back at Sephiroth using the Keyblade or Reflega.


 * Heartless Angel

Description: Sephiroth flies into the air, glows and calls out "Descend Heartless Angel". A halo appears over Sora's head, which after a delay, cuts Sora's HP to 1 and depletes all his MP, even if he is using a limit. This can be stopped by attacking Sephiroth before the halo appears, or by timing Curaga to heal Sora just after the attack finishes casting.


 * Firaga Wall

Description: Sephiroth draws Sora towards him and summons many flame pillars around him. These can be avoided by running away from Sephiroth, or using Reflega if Sora is caught in them.


 * Meteo

Description: Sephiroth floats into the air in front of the chasm and summons many meteors to hit Sora. These can be avoided with a combination of Aerial Dodge, Reflega and deft moving.

Preparations
Equip Sora with as much equipment to increase his defense as possible. Ribbons work well for this. The Ultima Weapon Keychain is the best to use. Also equip Sora with the following abilities; Guard, Counterguard, High Jump, Aerial Dodge, Slide Dash, Combo Boost, Air Combo Boost, Finishing Plus, Leaf Bracer, Defender and Once More. If you are at a higher level, MP Haste, MP Rage and Berserk Charge are also helpful. Also equip any other abilities to power up Sora's combos, and give him as many Elixirs or Megalixirs as possible. Equip Reflega, Curaga, the Elixirs and Megalixirs to Sora's shortcut menu. Level-wise, you should be at least at Level 50.

Phase One
Sephiroth always begins the battle with Flash, so hit the Triangle button as soon as the fight begins, then target Sephiroth. Flash leaves Sephiroth open for a while, so hit him with Slide Dash and unleash a combo until he teleports. After this, Sephiroth will usually walk after you, unleashing a Ground Omnislash when he gets close. Use Guard and Counterguard to deflect and interrupt the attack and counter with a combo.

If Sephiroth hits you with his Teleport Slash, he will follow up with Aerial Omnislash multiple times. Quickly use Aerial Dodge when he teleports and attack him when he reappears to minimize the damage. If Sephiroth uses Flash again, simply use the Reaction Command to avoid it. Curaga should be the main method of healing in this phase. The ability Berserk Charge will effectively disable Sora's finisher during MP charge, allowing you to attack Sephiroth more than you would with the finisher enabled, allowing your MP to charge while he is being attacked.

Sephiroth's moves in this phase can all be easily countered if you can recognize the signs of which attack he is using. With four of his health bars gone, Sephiroth will say "Know your place", signaling he is entering his second attack phase.

Phase Two
Sephiroth will now begin using Shadow Flare. You can bat the attacks back at Sephiroth with the Keyblade or Reflega - since the Shadow Flares appear surrounding you, the latter option is advised. Sephiroth will still use his various attacks from his first phase, so react accordingly. Sephiroth will also start utilizing his Firaga Wall, summoning multiple flame pillars around him while drawing you towards him. Run and jump away to avoid them, or if you're caught in them, use Reflega to protect yourself.

Sephiroth also begins using his trademark Heartless Angel attack. Watch and listen for the signs he's casting it, and use High Jump and Aerial Dodge to attack him before he completes the casting. Sephiroth floats high into the air while using this attack, so these two abilities are a must to reach him quickly and attack him, as it is impossible otherwise to stop him, barring you being close enough to him to hit him before he rises. If he casts it successfully, quickly use an Elixir, then prepare for the immediate Flash. Curaga's lag between casting it and it healing can also be exploited here; if the spell is cast so it starts before Sora's MP is depleted, but cures after the attack, Heartless Angel can be neutralized at the cost of MP.

Sephiroth in general becomes much more aggressive in this stage, so you will need to heal more often. Eventually, Sephiroth will summon a dark aura, and begin his final attack phase.

Phase Three
Sephiroth retains all his previous attacks, but performs them much more quickly and is much faster in general. Healing will be difficult this phase as Sephiroth's attacks come so fast that finding a safe opportunity can take some time. Typically, attacking after Sephiroth performs one of his moves from his first phase is a safe choice.

Sephiroth's new attack this phase is to rise in front of the castle in the background, out of reach, and use Meteo. Meteo hits many, many times, but the damage is negligible individually, but the sum damage of the attacks is potentially fatal. Through the use of High Jump, Aerial Dodge, Reflega, and deft running, you should be able to avoid the majority, if not all, of the attack. However, be careful not to use up all your MP on Reflega at this time.

At this point, it is mostly the same as Sephiroth's second phase, except that he attacks faster, making counter-attacking harder. Nevertheless, all his moves still have a specific counter to avoid or minimize the damage, so you merely need to be patient until he is vulnerable to attack. Guard and Reflega will be very helpful to survival.

Battle with Cloud
After the battle, Sephiroth is apparently unharmed and instructs Sora to find Cloud. Once Sora finds Cloud in the town square and tells him where Sephiroth is, he can return to the Dark Depths for a cutscene. Sephiroth and Cloud battle, and Sephiroth tells Cloud that beating him is pointless. Tifa arrives and Sephiroth attacks her, but Tifa gives Cloud "her light". This surprises Sephiroth, and the two leap into the air and vanish. Tifa decides to keep searching for Cloud and gives Sora the Fenrir Keyblade.