So I just noticed that Mirage Split and Nightmare’s End don’t exclusively have angel or demon wings.
Nightmare’s End (Sora’s keyblade) has angel wings on the handle and keychain, but above the handle you’ll notice the design is more reminiscent of a demon’s wing.
Mirage Split similarly has demon wings on its handle and keychain, but an angel’s wing above the handle.
(Angel wings circled in blue, demon wings circled in red)
This further suggests how Sora and Riku work in yin yang. One is not completely darkness and the other is not completely light. They balance each other out
