Ryan Zimmerman

Theory. The Master of Masters is actually Xigbar/Braig sent into the far far past by Xehanort to start the Keyblade War in the first place. It would explain why he told Luxu his eye was put into the Keyblade (eyepatch), it would explain why he's started planting seeds of descent into the foretellers, and it explains how he wrote the Book of Prophecies and why he was detailed with some points and extremely vague with other. Wild theory but if it's correct, jesus.