Winner's Proof

The Winner's Proof (ウイナーズプルーフ) Keyblade is acquired after finding and fulfilling the tasks of the Organization XIII Mushrooms, the thirteen Mushroom Heartless scattered around the worlds in Kingdom Hearts II Final Mix. They give you that Keyblade in the Hollow Bastion/Radiant Garden's canyon. This Keyblade, along with the Serendipitous Pair Keyblade, is a Kingdom Hearts II Final Mix exclusive.

Winner's Proof's name comes from the fact that you have to surpass twelve tests (one for each Mushroom, since the last one's test is to surpass the other twelve).

Winner's Proof displays exactly thirteen Mushrooms (four in the Keychain, two in the handle and the remaining seven on the blade, with one being the "sharp point" of the Keyblade). The Roman numeral XIII (13) is shown just above the hilt.

It is also the Keyblade with the highest bonus in Magic.