Two Become One

Serendipitous Pair (めぐりあう二人) is a keychain for Sora's Keyblade which appears in Kingdom Hearts II: Final Mix. It is obtained by defeating Roxas at Memory's Skyscraper. Serendipitous Pair represents Roxas, a fact borne out by its obtainment, appearance, and ability, Light & Dark, which causes the activation of any Drive form to put Sora in either Anti or Final Form. Serendipitous Pair is also one of the Keyblades Roxas can equip in Kingdom Hearts 358/2 Days.

Appearance
The Serendipitous Pair is one of the more sword-like Keyblades, possesing a notched blade with a noticeably sharp edge. Its color scheme is derived from a fusion of Roxas' Oathkeeper and Oblivion keychains, and the handle is composed of the same checkerboard pattern on Roxas' wristband. The Keyblade's design is also covered with references to Roxas' Nobody nature; the usual Nobody thorns make up the teeth and rainguard, the chain links are heavily stylized versions of the Nobody Emblem, and the full Nobody Emblem adorns the hilt. The token itself is Roxas' Nobody-thorn charm.Also as you can see the blade of the keyblade represents Riku's Way to Dawn keyblade supposingly representing sora's memories of Riku.