[Grimlockimus]

Kamen Rider Jam huh? Next we need a Kamen Rider Peanut Butter made out of the nut rider arms.

As for the identity of this new rider..it's hard to say since there's two theories I'm thinking sound plausible.

Ryoma: Combined the data from the Yoma and Kiwami lockseeds to make this new one. Plus the visor looks a lot like Ryoma's reguar Lemon Energy form.

Sagara: Helheim is and has always been the main threat in Gaim, and now that we know Sagara literally IS Helheim it makes sense he could be a final villain, or one to test Kouta one last time.

Plus then the name makes a bit more sense. DJ. JAM. DJ BRING THE JAMS.