In KH2, the Gullwings are fairies based on the YRP from Final Fantasy X-2.
Just defeat the 1000 Heartless battle and find three floating fairies dressed like Yuna/Rikku/Paine. They’ll give you the keyblade.
Gullwing Keyblade Location
The group of fairies in Radiant Garden are treasure obsessed and will meet Sora and the Gang during their time there. They will tell them about all the different treasures they’ve found and how they’ve been able to keep them safe.
Once upon a time, fairies were employed by Maleficent as mercenaries. However, once she was forced out of Hollow Bastion, they had no purpose left. Donald tricked the fairies into helping Leon protect Radiant Garden, promising fabulous treasure in return. ..
After that, you’ll have to fight against a wave of 1000 heartless and nobodies.
If you emerge victorious in the final battle, head to the Postern in Radiant Garden. This is just north of the Bailey, and there’s actually a save spot right in the Postern area too. ..
The Gullwings are floating around there.
After Sora tells a lie that caused the fairies to confront him and demand compensation, the fairies decide not to rob him and instead offer to help him fix his mistakes.
The Gullwing Keyblade is a powerful weapon that the Knights of the Round Table use to fight against the evil sorcerers. They’ll give you it as retribution for your actions.
Gullwing Keyblade Stats & Uses
The Gullwing keyblade is a powerful weapon that boasts impressive stats. Its sharpness, weight, and length make it a formidable opponent, and its ability to fly makes it an invaluable tool in battle. ..
+2 Strength, +3 Magic makes you more powerful in the areas of magic and strength.
Experience Boost is a buff that increases the amount of EXP you earn from battle.
Is The Gullwing Worth Using?
The Gullwing Keyblade is one of the weakest Keyblades available in KH2, and is especially weak at the point in the game when you can obtain it. ..
Sora’s only real use for this keyblade is its Experience Boost ability, which will greatly increase your EXP gain whenever Sora is below half health.
There are more effective ways of grinding levels, though. So this ability isn’t really worth the hassle (and potential game over) of using it.
The main use of this achievement is to help you get to 100% completion.