Zero-One also has his own bike, the Rise Phone, which will also serve as his cellphone similar to Kamen Rider Build's Build Phone. In addition, he has his own mecha, which the toy comes with the the Breaking Mammoth Key, while the Progise Holder comes with the Amazing Hercules Key.
The third Rider is Kamen Rider Horobi, which uses the Metsuboujinrai Forceriser and Sting Scorpion Key to transform. All three Kamen Riders have weapons that will turn into attache cases, and these weapons are: AttachCalibur (Zero-One), AttachShotgun (Vulcan), and AttachArrow (Horobi). There's also a rumored Rider named Kamen Rider Valkyrie, but based on the scans, it she might be just a rumor after all.
Take note, Kamen Rider Zero-One will be officially unveiled on July 17th. We will get more concrete information about the series on that day.
[Source: Tokunation, @Ben77878871 (link 2, link 3), @Shame082017, @TokuParadox, @TheRealMattHunt (link 2)]
UPDATE 1: Added more images and info courtesy of JEFusion.