Kamen Rider Dark Drive's real identity is that of Eiji Tomare, Shinnosuke's son. He was defeated by 108 a.k.a. Paradox Roidmude who had planned to time jump into the past as Eiji Tomari so that he can fuse his past & future form, hence the occurrence of Eternal Global Freeze.

As for the evil Krim Steinbelt, this Krim isn't evil at all. As we have witnessed in the last episode of Kamen Rider Drive, a virus was planted in the Drive Driver that made Krim lose himself causing Type Tridoron to go berserk and attack Mach. Krim orders Shinnosuke to destroy the driver so the horror of the coming future will not happen. Oh yeah, and the Krim that was passing by in the past few episodes was just a hologram.

In the heat of the battle against Dark Drive, Chase lends Shinnosuke his Mach Driver, tries to transform but fails. Shinnosuke uses the Tridoron Key that came came from the Next Deco Traveler and transforms into Super Dead Heat.

As for Kamen Rider Ghost, he has a a minute of air time in the movie with no establishing story like he just popped out of nowhere. When he uses his finisher, the Ghost Driver utters "Dai kaikan (great eye opening), Omega Drive!".

And then, for some miracle whip, Belt-san is revived using the Drive Driver that Eiji is wearing with the help of the Tridoron key and a dose of lightning. For Shinnosuke to use the Shift Next Special, Kiriko, with the help of Mad Doctor upgrades it so Drive can transform into Type Next Special.