Great Aether

Great Aether (, Great Sky or Great Aether) is Ike's Final Smash.

Overview
Ike becomes invincible and swings his sword in front of him; anybody who he hits is sent upward. He then leaps into the air after the sent character(s) and yells "Great...AETHER!!" while slashing the target(s) seven times with his sword aflame, after which he kicks them twice, slashes them four more times, and knocks them downward with a powerful finishing blow, similar to 's Triforce Slash. Upon impact with the ground, a large explosion knocks away the trapped character(s) and any character that happens to be too close. The DOJO!! described the move as a more powerful version of Aether.

The attack does up to 74% /60% /53% damage. The initial hit deals 5% in every game and is followed up by Ike throwing Ragnell towards the opponent(s), which (depending on how close the are to Ike and their position on stage) will deal 10% /3%. Ike will the unleash a series of slashes and kicks which deal 2% and 3% depending on the game and hit, with the last slash always dealing 5%. Ike and the opponents(s) then fall, dealing 5% /4% before landing with an explosion for 12% /10%. Because the knockback from the explosion is vertical, opponents may not be KO'd immediately due to the high blast lines on some stages. In most cases, however, the move does provide significant knockback to launch enemies off the screen. It usually KOs around 35% /15% /40%.

Multiple enemies can be picked up in this attack and, although Ike is invincible during this move, Ike's victims can be attacked by other players along the way down. The move elevates Ike to the highest point on the stage and typically takes place in the center of the stage. Due to the fact that Ike moves to the center of the stage when this move activates, on some custom stages the downswing can be somewhat of a Sacrificial KO. As a result, Ike moves to the side instead of the exact center when using the move on stages like Gaur Plain and Midgar (after Odin's slash).

On 75m, Rumble Falls, Flat Zone 2, Hanenbow, the elevated part of Rainbow Cruise, the World 1-2 version of Mushroomy Kingdom, and certain custom stages, it is essentially a guaranteed OHKO in every game, because the opponent is brought up to the top platform, very close to the stage boundary.

CPU opponents tend to get hit by this move, even if not caught in the initial strike. When they try to "add to the woes" of one caught in the move (as Sakurai suggested at DOJO), they do not understand to get out of the way when Ike plummets down, and get caught in the explosion.

Similarly to Eruption, the flames that are part of Great Aether are changed to blue in Smash 4, making it closer to Ike's origin in Fire Emblem than before.

Origin
Oddly, this move has never been seen before in the Fire Emblem series, although it may be inspired by several elements of Ike's story. Aside from being Ike's mastery skill in ' and ', it could be based on the final blow Ike deals to the goddess  in the end of Radiant Dawn. For this attack, Ike uses the power of the goddess to finish Ashera off, which wraps him in radiant blue fire and is the basis of the title given to Ike in the game's epilogue ("Radiant Hero" in English material, "Hero of Blue Flames" in Japanese; both come from the title of Path of Radiance in their respective language). The actual attack finishes with a downward plunge at Ashera, which is similar to the final hit of Great Aether. While the fires of Great Aether are regularly colored in Brawl, Smash 4 changed them to be blue to match Radiant Dawn.

 has followed similar naming conventions to Great Aether when introducing upgraded versions, such as Radiant Aether for Ike's "Legendary" variant. These upgraded skills are exclusive to each Ike variant and cannot be inherited to other units.

would eventually make its way back to the series in  as Emblem Ike's Engage Attack. However, instead of being a series of attacks before hitting the ground, the animation is more like his normal Aether before sending a massive shockwave that lifts rocks from the ground.

Trivia

 * When Ike first appears in The Subspace Emissary, he uses a regular Aether on the Ancient Minister to destroy the Subspace Bomb that he is carrying. However, in the English language version of the cutscene, he yells out "Great Aether" instead of "Aether". This is because the voice clip of "Aether" in Japanese is split in two parts between the characters (天空 Tenkū) and the extra word was used to fill the line. (The word "Aether" in English also has two syllables, but it arguably would not split as well.)
 * Despite this, 's Awakening Aether has "Aether" split into two distinct syllables, in line with the Japanese audio—this, however, was not the case in his initial reveal trailer.
 * The kicks that Ike does are almost identical to the first two kicks of Snake's neutral aerial.
 * In Brawl, while using this final smash, Ike and the opponent will slowly rise upward. If Ike's animations are sufficiently slowed down via mods, they will continue to rise until the opponent reaches the upper blast zone and gets KOed by the next slash.
 * As with End of Day, it is possible to self-destruct with this Final Smash if it is used on a custom stage that has a gap in the center.
 * When 3 pairs of Ice Climbers are trapped in a Great Aether, it is possible that the bigger space of characters can save them from being KO'd and save Ike from SDing on these types of stages. This can occur since all the characters trapped will make a wider collision bubble that can be hit by platforms that would not usually be hit with fewer characters and commence the final hit.
 * In, if Great Aether is used on Gaur Plain or Gerudo Valley after the bridge has been broken, Ike will instead bring the opponent above the closer side of the gap so that he doesn't SD.
 * An exception to this is if the player activates Great Aether during the Float Islands phase of, where Ike and the opponent will dive straight down to the blast line, resulting in a self-destruct; Ike must be facing right and standing on the left side of the stage for this to be successful. The same applies to with Omnislash.
 * In Ultimate, if Great Aether is used on a stage and the target disappears (such as Nana disappearing after Popo is KO'd), Ike will land on the main platform instead of the top platform.
 * In Brawl, if a player uses 's up aerial while Ike is in the middle of his Final Smash, it will push opponents or teammates (in Team Battles with Friendly Fire enabled) out of the attack, causing them to not get KO'ed, but leaving them in their tumbling animation until the Final Smash is finished.
 * It can also be done with 's side special.
 * In, if the Final Smash is used on Metal , he will lose his metallic texture.
 * Even though the attack's fire has been recolored in SSB4, the trails of the sword during the attack remain colored orange like in Brawl. This was changed in Ultimate, similar to Omnislash and Omnislash Ver. 5.
 * Despite the copious amount of fire visuals in the move, only the top of the final flame pillar in Ultimate has a flame hitbox; all other hitboxes in every other game is not a flame hitbox.
 * In Training mode, Great Aether along with other similar Final Smashes aren't counted in the combo meter.