Gigaflare

Gigaflare (ギガフレア), also known as Giga Flare, is a recurring attack in the Final Fantasy series. It is an upgraded form of Megaflare, and does massive non-elemenetal damage to all targets. As with Megaflare it is most often used by Bahamut or very strong bosses.

Final Fantasy V
In the GBA release, the superboss Enuo can use Giga Flare.

Final Fantasy VII
Neo Bahamut uses Giga Flare when summoned into battle.

Final Fantasy XI
When Bahamut is fought in Storms of Fate, when he falls to 10% of his HP he uses Gigaflare. In the subsequent Wyrmking Descends encounter, he uses Gigaflare much sooner.

Final Fantasy XII
The final boss The Undying, a mechanical Bahamut formed by Vayne merging with pieces of the airship Sky Fortress Bahamut, uses Gigaflare Sword.

Final Fantasy XIII-2
Jet Bahamut, the final boss, is able to use Gigaflare.

Final Fantasy Tactics
Archaeodaemon can naturally use Gigaflare. Behemoth can also use it when an ally with the Beastmaster ability is next to it. It does high damage to a large area.

Final Fantasy Tactics Advance
Giga Flare is a very powerful, area of effect attack used by the Sage. This move is learned from the Scorpion Tail for 300 AP and costs 40 MP to cast. It has a range of 3 and a Magic Power of 65, cannot be reflected, and is stealable through the ability Steal: Ability. Though it cannot be reflected, it can be countered with Return Magic, and MP can be absorbed from it through Absorb MP.

Final Fantasy Tactics A2: Grimoire of the Rift
Gigaflare returns as a spell for the Sage class, costing 32 MP to cast and having a range of 3. It is learned from the Lotus Mace for 300 AP and deals heavy non-elemental damage.