Game:Xion

Xion is fought as a boss in Kingdom Hearts 358/2 Days and Kingdom Hearts III. In Kingdom Hearts 358/2 Days she is fought multiple times throughout the game before finally serving as the penultimate boss.

In Kingdom Hearts III, she and Saïx team up with each other at the Keyblade Graveyard to fight Sora, Kairi, and Lea. A data replica of her is also an optional boss in Kingdom Hearts III Re Mind.

Kingdom Hearts 358/2 Days
In Mission 75, Roxas is sent to Twilight Town. Xion has left the Organization and is mistaken for the Organization impostor, Riku. Roxas has to track her down and "eliminate" her. Roxas attacks the impostor, but is stunned to realize he is fighting Xion.

She attacks Roxas in Mission 92, which takes place throughout various locations in worlds visited during the events of the game. Using the Organization XIII Devices, Xion is able to absorb Sora's memories from each world in order to replicate his abilities, and to some extent other elements of those worlds. For example, in Halloween Town, Xion uses Sora's Ragnarok and uses a weapon resembling the Chimera arm or The Experiment's arm, while in Agrabah, she uses his Ars Arcanum and has arms and swords resembling Kurt Zisa. Strike Raid is the only one of Sora's Kingdom Hearts special abilities that Xion does not use. Interestingly, the first three areas that Xion warps Roxas to are the locations of that worlds' respective Keyholes. In the case of Twilight Town, the Station Plaza is where Sora opens the world Gate.

Design
During Roxas's battle with Xion, she dons armor which changes a number of times throughout the fight. Her basic form is a bizarrely-shaped, predominantly silver and black suit, with dull red armor near her waist, gold on her boots, and orange armored gloves. Xion's helmet sports two black spikes that jut out horizontally on either side, and a large, red Nobody symbol on the faceplate, part of which forms something of a horn on the top of the helmet. This form is based on Sora's original appearance, with Sora's jacket, pants, and necklace, although Xion's pants are pink and have designs, and her necklace features a Nobody symbol instead of a crown.

In her first form, Xion sports large, skeletal, colorful wings and a huge, orange and red, intricately-shaped sword. In her second form, Xion loses her wings and grows to twice the size of Roxas, exchanging her sword for a large, pincer-like weapon vaguely resembling one of the Chimera's arms. In her third form, Xion transforms into a figure with four huge arms, decorated with elegant gold, purple and red designs. She has large blades instead of hands, and her arms resemble Kurt Zisa's arms. Her main body is slightly larger than normal in this form.

In her final transformation, Xion grows to a titanic size, about the same height as the Train Station tower in Twilight Town. Her armor is now embroidered with numerous spikes and ribbons, and she gains two pink and silver, Keyblade-like weapons with teeth in the shape of the Nobody symbol. Interestingly, this form has a similar design to Sora's appearance in Kingdom Hearts II, now being mainly black and dark grey.

Mission 75
Roxas may get stuck fighting the many Heartless in this mission during the search for Xion. Moving further into the Tram Common, Roxas sees Xion on top of a building, and she runs away. Xion does not attack, but only runs and dodge rolls, and teleports to another place in the area after taking several hits. The system for when this mission ends is unclear, as the timing for Xion to go to the secluded area is set at random. At the end of the mission, Xion teleports herself to the secluded place, where she waits for Roxas. Once Roxas reaches Xion, the mission ends, following a few cutscenes.

Mission 92
Be prepared for a multi-stage boss battle. During the fight, Xion transports Roxas to four different locations, each time assuming a different form.

Xion's attacks require good timing and careful maneuvering to avoid. Make good use of Dodge Roll and Glide. Equip Cure magic and/or Potions. Attack magic is effective but not essential.

First Form
The first battle with Xion takes place in the Bizarre Room of Wonderland.

Second Form
The second battle takes place in Halloween Town, at the Manor Ruins.

Third Form
Xion's third battle takes place in the Lamp Chamber area of Agrabah. In this form, Xion is more graceful and agile, performing flips and spins that make her difficult to hit. Xion's third form is difficult to dodge due to limited dodging room combined with Xion's agility and long reach. Land combos immediately after she stops attacking, and move away before she resumes.

Final Form
The final battle with Xion takes place in front of the Train Station in Twilight Town. She becomes massive, but remains stationary at one end of the battlefield throughout the fight. In this form, Xion loses both Counter Slash and Barrier, and her regular attacks are slow and telegraphed. However, her attacks can inflict status effects.

Kingdom Hearts III
Xion is fought at the Keyblade Graveyard alongside Saïx. Sora has Kairi and Lea as allies. Xion starts the fight wielding the same weapon as Saïx, then switches to wielding her Replica Kingdom Key halfway through the fight. The techniques she uses depend on the weapon wielded.

If Sora is nearby immediately after Xion switches to the Keyblade, she uses Berserk Combo. She also uses this attack as a counterattack.

Xion will often teleport occasionally to Sora or Kairi's position. Once she reaches her target, she will use multiple Keyblade thrusts to send the target flying into the air, ending her combo with her slamming them down with her Replica Claymore. She will also occasionally enter a berserk state like Saïx's but the attack can be blocked by locking onto her. After one minute when Saïx's berserk gauge becomes full, Xion goes limp and stops acting, becoming invincible while in this state. Saïx then uses his Blue Berserk Burst attack, upon which a cutscene plays and afterwards Xion is no longer fought alongside Saïx, instead becoming Sora's party member for the rest of the fight.

Kingdom Hearts III Re Mind
Xion's data is a secret boss in Kingdom Hearts III Re Mind. Her battle is made significantly harder.

Xion retains a few attacks from her battle at the Keyblade Graveyard, such as Strike Raid, her basic combo, and her rushing combo. However, she now has more attacks at her disposal. Like Roxas, Xion often teleports in streaks of light and summons light beams to attack. Her blue light beams can temporarily reduce Sora's maximum health if they connect, stacking until Sora only has 1 HP - but, they can be blocked. Sora can use a Panacea, Elixir, or a Formchange to reverse the effect. Xion's golden light beams do not have the max-HP-reduction effect, but they cannot be blocked.

If Xion's revenge value is hit, she will teleport away and may perform a downward strike in the air above Sora. Dodge to avoid it.

Xion uses the following attacks in her first phase:
 * Fast Strike Raid combo: Xion performs Strike Raid 3 times in a row. Block all three, and the third will break Sora's guard. Risk Dodge to get a chance to attack.
 * Strike Raid into physical combo: Xion performs Strike Raid only once, followed by a 2-hit physical combo and a 3-hit physical combo, with a wide swing at the end of the 3-hit set. Block each hit and reprisal the last hit of the 3-combo for a chance to attack. A good visual cue is Xion's wide swing at the end, which leaves her low to the ground.
 * Slow blue beams: Xion fires blue light beams one at a time. Block 4 beams and Airstep to her as she fires the 5th beam to get a chance to attack.
 * Strike Raid and blue beams combo: Xion performs one Strike Raid, followed by one blue beam, a second Strike Raid, two blue beams, and finally a third Strike Raid that breaks Sora's guard. Block each, and Risk Dodge after the guard break for a chance to attack.
 * Blue beam dashes: Xion dashes sideways, launching blue beams to her sides as she does so. There does not seem to be an opening to this, just block the beams.
 * Keyblade flurry: Xion rushes at Sora, wildly swinging her Keyblade for 4-5 hits, followed by a downward strike. She then teleports and attempts a second downward strike, followed by another teleport and a third downward strike. There does not seem to be an opening for this - block the initial flurry, then block or dodge the downward strikes.

If Xion glows golden and gains armor (often paired with the lines "Now you'll see!" or "Time to end this!"), she is entering her armor phase. Until her armor is depleted (or enough time passes), her attacks will change to the following:
 * Bouncing attack: Xion jumps toward Sora and slams the ground with a golden flash, summoning gold pillars and sending blue beams outwards. She performs 5 slams in total - the first targets Sora and can be blocked, slams 2 through 4 are distant but their blue beams still need to be blocked, and slam 5 targets Sora again. Block each of the 5 slams, using a reprisal on the 5th slam for a chance to attack.
 * Keyblade flurry and blue beams 1: Xion rushes at Sora with wild Keyblade swings and a downward strike, followed by 4 fast blue beams, a single downward strike, and ending with 4 more fast blue beams. All attacks in this sequence can be blocked.
 * Keyblade flurry and blue beams 2: Xion rushes at Sora with wild Keyblade swings, but does not perform a downward strike. She follows this with 4 slow blue beams, and 4 fast blue beams. Block all of these.
 * Aeroga: Xion raises her Keyblade skyward (often paired with the line "Let it rain!") and summons large Aeroga pillars on the ground, 3 times total. These cannot be blocked, so dodge each as they appear.

When Xion has about 5 bars of HP remaining, she enters her second phase and adds additional attacks:
 * Physical combo with blue beams: Xion sends a set of 2 blue beams, performs 2 physical combos (which will usually miss), and sends another set of 2 beams from behind her. She then teleports and performs a wide swing, sending 4 blue pillars in the direction she swung in. Block the 2-beam sets, then block the wide swing and reprisal for a chance to attack.
 * Strike Raid and blue beams: Xion does 2 downward strikes with her Keyblade, followed by throwing 3 Strike Raids. The first Strike Raid stops before reaching Sora, and sends blue beams outwards. The second Strike Raid hits Sora, then sends blue beams outwards again. The third Strike Raid breaks Sora's guard and sends blue beams in an X shape towards him. As before, block each attack until reaching the guard break on the third Strike Raid, then Risk Dodge for a chance to attack.
 * Single downward strike: Xion occasionally will teleport 3 times and then perform a downward strike.

If Xion teleports outside the bounds of the arena (often paired with the line "Ready, Sora?" or "Here we go!"), she is performing her ultimate attack. The arena becomes bathed in a golden light, and the sky changes into a sunset. Xion will gain armor again, will not stagger during this phase, and her attacks will change until the armor is depleted or enough time passes:
 * Light eruption: Light erupts from the stage from the center outwards, in a pattern similar to the spokes of a wheel. Xion then rushes at Sora for a 3-hit physical combo. Light then erupts from the stage again, and Xion performs another 3-hit combo. The eruptions cannot be blocked, but Xion's physical attacks can - so dodge the former and block the latter. Try to reprisal on the physical attacks to deplete some of Xion's armor.
 * Blue beam cage: A cage of blue beams appears around Sora, followed by an unblockable golden beam in the center, and the blue beams scatter across the arena. Dodge once the yellow beam appears, then block the blue beams as they scatter.
 * Blue beam wall: Xion performs a downward strike, followed by a 3-hit combo while blue beams form a wall at her sides. All of these hits can be blocked and reprisaled.
 * Blue beam dance: Blue beams appear at the edges of the arena, then quickly move around it in sweeping motions, as Xion performs sideways dashes that send out more blue beams. Focus on blocking the beams.

After Xion's ultimate attack concludes, the light vanishes and Xion re-appears in the center of the arena. She is open to attack right as she re-appears.

Trivia

 * During Mission Mode, while battling Xion, she will not speak, due to some of her battle quotes being about Roxas.