Proof

The Proofs are a set of three key items, exclusive to Kingdom Hearts II Final Mix, which are obtained after completing specific side-missions.

The Proof of Connection is obtained by defeating the Lingering Will, the Proof of Nonexistence is rewarded after defeating all of Organization XIII's Replica Data, and the Proof of Peace is given after appeasing the entire Mushroom XIII.

Crowns
New costume modifications, known as Crowns, are unlocked by obtaining Proofs. These are equipped on Sora automatically and are present at all times, except during cutscenes and while Sora is in a world-specific costume. There are several types of crowns; possessing one Proof grants Sora a Copper Crown, two a Silver Crown, and all three a Gold Crown. They are purely cosmetic, and have no effect on gameplay.