[mrinfobox]

Here’s the whole suit.

Head:

The eyes are made of what appear to be two asymmetrical cross swords. It’s like Build but with no bug eye portion. Left side sword’s “horn” is slightly fire like and end in a forked style. Right side horn has 5 points 3 of which are joined like a wing with the right “horn” looking more like a jagged sword.

There’s a large unicorn like horn in the center front of the head behind the crossed swords. It has a computer chip like texture on the middle of the sides. Hard to tell what the texture really is.

Mouth is pretty standard but it joined in the center by the unicorn horn splitting the face in 2. Right side of mouth has a fang detail while the left doesn’t.

Upper Body:

Left arm is smooth but has a terraced type detailing on it. Right arm has 2 horned dragon head motif at the top with the bottom of the jaw on the right side of the chest and three diamond like spikes over the right chest. Left chest and side of body is smooth save for the same terraced details from the left arm. There are spines on back but they’re not huge. Body is split by a bar running through it. “Muscle details” at the bottom. Rider is clearly dragon themed in whatever form this is but the form only seems to visually effect half of his body.

Lower Body:

Long, segment detailed leg cloak like Kamen Rider Paradox Perfect Knockout Gamer but it only covers the right leg and goes all the way to the foot. Left leg shares the same detailing as the left arm. Both boots are identical.

Belt:

Belt appears to be a blade in a sheath with some sort of hinged mechanism on the top right of it. Some sort of item that appears to open like a book. What I assume is the gimmic if the blade itself isn’t. Appears to be textured with a computer chip like texture on the bottom front and possibly runes or glyphs on the upper back portion behind the hinged mechanism.
Blade handle sticks out of the right side of the driver.
Belt has 2 attachments on left and right sides. Not identical. Looks like they might hold sword and or henshin gimmic.

This could very well be a second form but given how early we got to see it I assume it’s the primary form.