Ultraman Mebius Side Story: Armored Darkness - STAGE II: The Immortal Wicked Armor 2008

Synopsis

While the Subordinate weeped, Mirai informed him that Ryu was alive, saved by the power of Ultraman King. He revealed that after Alien Emperor's defeat, Armored Darkness had been known for some time and Ultraman Hikari was sent by Ultraman King to destroy it before it could reach Earth, but the Armor's strength overpowered him and possessed him.