Saber + Zenkaiger: Superhero Senki movie brochures are currently being given to fans and this is how it looks. The brochure features Touma & Kaito performing double Henshin with Kamen Riders and Super Sentai behind them. When they transform, there is going to be a large explosion behind them.
Kamen Rider 1 & Akarenger are seen leading their teams. By the way, what are the Sentai looking at? Is it big monsters? or just the Kaijins standing on the top of the hill?
Kamen Rider Saber is confirmed to use HaouKen Xross Saber in the movie.
There must be a pretty good reason why it's Grand Zi-O and not Kamen Rider Zi-O in his base form.
Story Guide from the Brochure
"Touma Kamiyama (Kamen Rider Saber) has fallen into a slump and can't continue to write his book. He is worried. Yuri (Kamen Rider Saikou) approaches him and recommends he read a particular book. When Touma opens that book, a light engulfs him and when he opens his eyes, he finds him, Mei & Yuri surrounded by Kikainoids. They are teleported to Zenkaiger's World.
At the same time, Kaito Goshikida (Zenkaizer), Gaon (Zenkai Gaon), Magine (Zenkai Magine) & Vroon (Zenkai Vroon) get teleported to Kamen Rider Saber's world where they meet Rintaro Shindo (Kamen Rider Blades).
Touma decides to co-operate with Kaito to restore the world. Kamen Rider & Super Sentai of the past join them. Both the Heroes gather. They try to figure out the reason why the borders between the worlds disappeared. They meet the mysterious boy who is the key to all of this".
A new scan from one of the upcoming episodes of Kamen Rider Xross Saber where he is seen standing along with Kamen Rider Sabela and Kamen Rider Durendal (you can see his mask slightly on the left).
A new scan of Carmeara from Ultraman Trigger: NEW GENERATION TIGA. She seen under the ruins may be on Mars. She will say "...I found you. Trigger".