Royal Pretender

The Crown Pretender is a Heartless that appears in Kingdom Hearts Union χ. It acts as the last boss of the "Let's help the captured wielders!" quest chain during the Halloween Memorial Event in 2017.

Kingdom Hearts Union χ
On Halloween, Player goes to meet the members of their party in what seems to be an abandoned house. Though they and Chirithy initially believe that their friends just wanted to scare them, they soon realize that this is not the case. Upstairs, Corridors of Darkness open and lead to each of Player's friends being sealed within chests by the Crown Pretender and its minions. After confronting each of the lesser Heartless and freeing their friends, Player eliminates the Crown Pretender, allowing the party to carry on celebrating Halloween.