Game:Young Xehanort

Young Xehanort is an optional boss in the North American, PAL, and Final Mix versions of Kingdom Hearts Birth by Sleep. His boss battle is unlocked when the player defeats Vanitas Remnant, then returns to the Land of Departure on a save file in which it is still accessible. Despite this odd situation, his scene is within canon, and is considered to occur at the save file's point in the story. Defeating Xehanort grants the player a unique Keyblade named "No Name", but he can be refought by leaving Land of Departure and then returning.

Young Xehanort is also the penultimate boss of Kingdom Hearts 3D: Dream Drop Distance, battled by Riku as he desperately tries to save Sora from Master Xehanort.

Abilities
Young Xehanort has a variety of powerful attacks, all of which can defeat the player instantly if unprepared. However, nearly all of these attacks can be blocked or dodged with practice.
 * Short combo: Attacks with three quick strikes.
 * Long combo: Attacks with an extended sword combo.
 * Dash attack: Transforms his blades into a spear and dashes forward, then flips backward.
 * X wave: Jumps back and releases an X-shaped shockwave from his blades that tracks the protagonist.
 * Spear orbs: Summons several orbs that fire spears of energy at the protagonist from every direction. This attack can continue during the Unknown's other attacks.
 * Sonic Blade: Quickly darts around the battlefield, knocking the protagonist high into the air when he hits them.
 * Whirlwind to the void: Summons a tornado that scatters the protagonist's Deck Commands when it hits them.
 * Vanish: Becomes invisible, and cannot be locked-on - though it is still possible to track him via his blades, which are only visible when he attacks.
 * Raging Storm: Summons three vortexes of flame around himself and hovers around the battlefield. The flames stun the protagonist when they hit them. In later phases of the battle, he will combine Raging Storm with some of his other abilities, usually his Long Combo.
 * Summon copies: Summons four copies of himself to overwhelm the player. All of them have every single one of his abilities (except for Vanish, and naturally, this one), and there is no set pattern to which attacks they use when.  Can easily be defeated by a clean hit, however.
 * Mega Flare: Summons a huge sphere of flames that explodes, inflicting massive damage and sometimes igniting the protagonist.
 * Meteor: Summons a meteor to fall on the battlefield and explode.
 * Doom: Fires a web of energy at the protagonist and starts a five second countdown. The player must rapidly tap to end the attack, and if the countdown reaches zero they are defeated.
 * Collision Magnet: Leaps into the air and casts out a lasso of energy that snares the protagonist and pulls them toward him for a quick slash. In the Final Mix version of the game, Xehanort's Collision Magnet was weakened to make it easier to dodge.
 * Renewal Barrier: If the player attacks him head-first without an opening, or attacks constantly with a long combo, he will parry the player's attack and recover a bit of health.
 * Time reversal: At any random moment when the player deals damage to him, he could potentially stop and reverse time to the precise moment before the player hit him. As soon as time is restored, he uses one of his other attacks before the player can react.

Strategy
Young Xehanort is a powerful boss and one of the stronger enemies in the game. His attacks are varied and hard to predict, similar to those of the Lingering Will. Not only is he immune to all status effects, but he has a great deal of HP as well. The boss is very swift, with his attacks generally reducing the player's HP to 1. Xehanort is also adept in defense; he can turn mostly invisible, although he can still take damage and can be located due to his faint shimmer, and he sometimes rewinds time after taking damage, allowing him to recover some of his lost HP.

As Xehanort's HP dwindles, he goes even further on the offensive. He will often start one of his long-duration techniques, then continue to attack with different techniques while the first one is playing out. Xehanort will also clone himself, creating four copies that can attack and move independently of the Xehanort. His most frustrating tactic is to snare the protagonist with his Collision Magnet, then immediately follow it up with another Collision Magnet, a sword combo, or a Whirlwind to the Void, none of which the protagonist is given the chance to avoid, resulting in an immediate game over (although there are very rare occasions in which the player can escape before Xehanort strings together another attack). Collision Magnet can be avoided easiest by simply dashing towards Xehanort when he jumps in the air, and also seems to be canceled if Xehanort pulls the player up against a wall.

Xehanort will attack whenever an opening to do so presents itself, but it is easy to heal safely by simply dashing far away from him first with either Slide, Dodge Roll, or Cartwheel. It is also somewhat easy to guard against his attacks by mashing, so the protagonist can also heal by using Renewal Block or Renewal Barrier. Because Xehanort leaves little time for the protagonist to act, it is unwise to use any advanced or ultimate commands, as they take too long to fire and reload. Shotlocks are also good options, but Xehanort likes to evade the targeting reticule, and can often evade damage midway through by using its Renewal Block, which will also heal him. If the protagonist decides to rely on Shotlocks, they should stock many Elixirs in order to make sure their Focus Gauge never runs out. D-Link's are also ill advised, as Xehanort may turn invisible in response. Finally, the Keyblade and Finish Command equipped are not very important, as Xehanort leaves no time for Keyblade strikes. The protagonist's Keyblade should be chosen only for its stat boosts, preferably towards the Attack stat.

The safest and simplest way to defeat Young Xehanort is to simply use a deck of 2-4 Cure-type commands, and fill the rest with Thunder Surge commands. Although Fire Surge is equally effective as a command, the Thunderbolt Command Style, triggered by the Thunder Surges, has an easier time hitting Xehanort than Firestorm does. A good way to set the deck is to have Thunder Surge, Cure, Thunder Surge, Cure and so on, so that both commands are easily accessible and it also helps with not needing to cycle through commands that are reloading. With this deck, the protagonist can basically use Thunder Surge over and over, even when Xehanort is invisible, damaging Xehanort if they hit him and often knocking him out of his combos. The protagonist should make sure to use Thunder Surge so that he goes through Xehanort and winds up a short distance past him, rather than next to him, but should dash away instead if Xehanort is right next to the protagonist, as Thunder Surge has a tiny but noticeable start-up lag. Thunder Surge can even be used as a pseudo-dash in order to avoid Xehanort's techniques, like his Collision Magnet. If the protagonist is ever hit by an attack, he should immediately start dashing away, normally, and heal with Cure as soon as he is clear from Xehanort. The player can also use Wingblade, which allows him to hit Xehanort with a combo of Keyblade attacks that he can't easily break out of. Even after setting up a working deck and overall strategy, victory against Xehanort relies primarily on luck, due to his penchant for using unavoidable, instant-death combos.

Kingdom Hearts 3D: Dream Drop Distance
To provide for defense, Riku should equip Dark Barrier, Counter Aura, Leaf Bracer, Second Chance, Once More, and Slow Block. His Command Deck should include homing attacks like Balloonga or Dark Firaga, as well as powerful attacks like Dark Splicer and Shadowbreaker, and healing commands like Curaga.

Young Xehanort is an aggressive fighter and it can be difficult to score hits on him as he can trap Riku in a flurry of combo attacks that rapidly drain his health. Dark Barrier followed by Counter Aura is the most effective way of damaging him, although keep in mind that some of his attacks, such as when he fires a barrage of lasers or turns his Keyblade into a whip, are unblockable and should be evaded using Shadow Slide. Xehanort tends to warp away from projectiles and attack commands but it is possible to use them against him when he pauses to launch his own ranged attacks. Be extra cautious if he shoots dark projectiles at Riku, they inflict Slow so quickly cure it with Esuna or a Panacea if Slow Block is not equipped.

Once Xehanort's health has been depleted, he will freeze time and warp into the giant Clock that appears in the centre of the arena. Attack the Clock quickly until the option to perform a Reality Shift appears. This will trigger the final stage of the battle. If Riku takes too long to activate the Reality Shift,then Xehanort will rewind time to the beginning of the fight and regain some of his health (approximately two and a half life bars). His health will have to be depleted again in order to have another chance to perform the Reality Shift.

In the final stage of the fight, Xehanort remains inside the Clock which is now vulnerable to attack. Whilst he doesn't attack Riku directly, he creates clones of himself to defend the Clock. These clones are invincible and will attempt to swarm Riku with continuous combos and projectile attacks, whilst it is possible to block these attacks, it is safer to use Shadow Slide to evade them. During the brief moments when no clones appear, the Clock is open to attack. Be warned though, if too much time passes and Riku fails to destroy the Clock, Xehanort will rewind time to the start of the fight, but will only have two and a half bars of health.