Wrong section but you do it by attaching the Griseous Orb to him, which you find by going in the portal to the Distortion World you find in Turnback Cave.
Δloyisious ☆ Divo |Haza D'Ξvil The poison that is always fatal... yet the stinger won't stop stinging
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Yep, they're right. But this doesn't even require a new topic. In the d/p section of the games, there is actually a thread just for questions like this, just fyi...