Dark Aura

Dark Aura, also translated as Dark Rush in Kingdom Hearts Union χ, is technique introduced in . It is a signature move of Riku, and it appears repeatedly throughout the  series. It typically allows the user to rush enemies repeatedly from all directions, finishing by plunging their weapon into the ground, releasing columns of energy radially. The attack often deals damage.

There is a variation of Dark Aura exclusive to Kingdom Hearts II in which Riku launches spheres of dark flame at the opponent, a technique similar to Dark Firaga.

Mechanics
In Kingdom Hearts Chain of Memories, Dark Aura is an attack sleight that Riku can use while in Dark Mode. When used, Riku performs 6 rush attacks at the enemy before following with a groundward attack that generates pillars of light and a shockwave. The columns of light that conclude the attack may enemies when hit.

In Kingdom Hearts II, Dark Aura is an action ability available once Riku joins the party. So long as Riku is in the active party, whenever Sora completes an attack combo, the player can press to execute the Dark Aura Reaction Command, in which Riku fires spheres of dark flame that can stop enemies on contact. It costs two to equip and ten MP to use. During the final battle with     when the player is forced to play as Riku, Dark Aura can be used by pressing.

In Kingdom Hearts 3D: Dream Drop Distance, Dark Aura is an exclusive to Riku that uses two slots and has a reload time of 42 seconds. It grants +4 to Strength and +10 to Dark Resistance when attached to a Dream Eater recipe. When used, Riku performs 8 rush attacks at the enemy before following with a groundward attack that generates pillars of darkness in a sphere around the dive impact.

In Kingdom Hearts Union χ, Dark Aura is a special attack that targets all enemies. In the English version, Dark Aura +5 costs 0 special attack gauges to perform, and raises the user's general strength by 1 tier for 1 turn. In the Japanese version, Dark Aura +5 costs 3 special attack gauges to perform, and raises the user's general strength and defense by 1 tier for 1 turn.

In Kingdom Hearts Union χ, Dark Rush is a special attack that targets all enemies. It costs 4 special attack gauges to perform. It lowers the general defense of all enemies for 2 turns. It inflicts more damage the higher the slot number.

Kingdom Hearts Chain of Memories

 * Riku learns Dark Aura once he obtains the ability to enter Dark Mode.

Kingdom Hearts II

 * Riku has Dark Aura as a default ability.

Kingdom Hearts 3D: Dream Drop Distance

 * Sora and Riku can purchase Dark Aura from the Ghostabocky Ability Link for 400 Link Points.
 * Sora and Riku can purchase Dark Aura from the Keeba Tiger Ability Link for 400 Link Points.

Kingdom Hearts Union χ

 * Dark Aura +5 is the special attack of medal.
 * Dark Aura +6 is the special attack of medal.
 * Dark Aura +7 is the special attack of medal.
 * Dark Rush +5 is the special attack of medal.
 * Dark Rush +6 is the special attack of medal.

Other appearances
Riku is fought several times as a boss throughout the Kingdom Hearts series. Dark Aura serves as one of his desperation attacks in each of these encounters.

Kingdom Hearts
When Sora faces Riku for the second time while Riku is under the possession of Ansem, Seeker of Darkness in Hollow Bastion, Dark Aura serves as Riku's strongest attack. It is used when he is low on HP and his hand is glowing in a sphere of dark energy.

Kingdom Hearts Chain of Memories
As a Replica created from the real Riku's combat data, the Riku Replica can utilize all of Riku's abilities which are exclusive to Dark Mode. Unlike Riku, who needs a card value of 27 to execute Dark Aura, the Riku Replica can use it with any value, granted he only gains access to the Sleight during his final battle with Sora in the main story and Riku in Reverse/Rebirth.

The finisher of the Riku Replica's version of Dark Aura has about two times the range of the real Riku's.

Kingdom Hearts 358/2 Days
During his battle with Roxas in The World That Never Was, Riku is able to use Dark Aura once he charges the Oblivion Keyblade. Rather than attacking while teleporting over the whole arena, Riku simply attacks Roxas's position. In Mission Mode, Anti-Riku can use Dark Aura as well.

Kingdom Hearts Re:coded
Data-Riku during his third phase and Data-Riku (Bugged) can use Dark Aura.

Trivia

 * In Kingdom Hearts 3D: Dream Drop Distance, if Riku is caught in a Kooma Panda's Tea Table Flip during the initial start-up of Dark Aura, a glitch will occur that causes him to pass through the floor and remain in the animation until the player resets the game.