Royal Pretender

The Royal Pretender is an Emblem 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, 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 wanted to scare them, they soon realize that this is not the case. Upstairs, Corridors of Darkness opens and leads to each of Player's friends being sealed within chests by the Royal Pretender and its minions. After confronting each of the lesser Heartless and freeing their friends, Player eliminates the Royal Pretender, allowing the party to carry on celebrating Halloween.