Kamen Rider Gaim: Final Stage 2015 (Japan), also known as Kamen Raidā Gaimu Fainaru Sutēji , is Japan drama premiere on Feb 15, 2015
Those who have died - Hase, Sid, Yoko, Kaito, the Professor and Over Lords - are gathered together by a mysterious being known as Maja, who seeks to take over the world. He brainwashes them to do his bidding. Kamen Rider Maja once was a presence that witnessed the erosion of the Earth brought on by Helheim and Sagara, and now he takes action to claim the Earth for himself.
This is considered non-canon to the Gaim series, as how Zack got back his Sengoku Driver in this stage show is contradicted by Kamen Rider Gaim Gaiden: Kamen Rider Knuckle.