In Kingdom Hearts III, Donald Duck casts a move called "Zettaflare" which is a more powerful variant of the usual "Flare" cast. Flare is a common black mage ability in the wider Final Fantasy series, but there are more powerful variants of the spell seen in the games.
- Flare is a high level magic spell
- Megaflare is Bahamut's signature ability
- Gigaflare is Neo-Bahamut's attack
- Terraflare is Bahamut Zero's attack, it is also the attack used by Bahamut to reset the world in Final Fantasy XIV
- Petaflare is the final attack Bahamut SIN used in Final Fantasy VII: Advent Children
- Exaflare belongs to Bahamut Fury, Bahamut Prime, and Midgardsormr
Zettaflare has never been used by any enemy in a Final Fantasy game. Granted, Kingdom Hearts is not in the FF series, but it does utilize many Final Fantasy characters and tropes. Specifically, the magic system in Kingdom Hearts is straight out of Final Fantasy with its magic tiers.
As the flare tiers are based on Greek prefixes, we can estimate the amount of difference between the tiers.
- deca – 101 – 10
- kilo – 103 – 1,000
- mega – 106 – 1,000,000
- giga – 109– 1,000,000,000
- tera – 1012 – 1,000,000,000,000
- peta – 1015– 1,000,000,000,000,000
- exa – 1018 – 1,000,000,000,000,000,000
- zetta -1021 – 1,000,000,000,000,000,000,000
Which means Zettaflare is one thousand exaflares or a septillion flares. Which is goddamn insane.
Especially since no one else in the extended Final Fantasy universe is capable of casting it. Not even the series' most powerful enemies have come close.
Which means that Donald Duck is the most powerful being in the wider Final Fantasy universe and could probably nuke solar systems.
Yes, this guy.