The Undead Core (アンデッドコア Andeddo Koa) is a possessed version of the Core and the final boss battle fought on the Balcony. It is fought alongside alternate forms of Misery and Sue Sakamoto, who were both influenced by the Red Crystal's power shortly before the fight commences. The Core, in its "undead" form, retains its ability to counteract Ballos's power and keep the island afloat with the balance.