The Evol Bottles are for Evol. Those are Evol Rabbit and Evol Dragon, not new forms for Build and Cross-Z - the text confirms this.

The names for Riders and their forms have gotten rather lousy. Grease and now Genius Form? I'd prefer Genius having regular compound eyes instead of bottles where the eyes should be, but it's not bad. I like the imagery of Sento being hooked up to all of the bottles at once like some kind of monstrosity.

I really don't care for what they've done with Cross-Z. Charge should have come later in the show if they wanted him to get a Sclash Driver, not so soon after he debuted; or just skipped the "Mark I" Cross-Z altogether and start with Charge. Banjo going back to his first belt with a new upgrade, all while seemingly dropping the Cross Dragon and his sword, makes it rather pointless. At least when Kaito went back to the Sengoku Driver it was because the Genesis Driver was rendered inoperable.

Speaking of the sword, at least Charge makes sense in that Banjo, being a boxer, uses his fists more than other weapons. It seems a case of the character not quite matching the powers and arsenal.

A rumour's flying around about insert themes

Tensai Tenshi (Angelic Genius for the non weebs) by Kamen Rider Girls, BE OUR ONE by Beverley, WAKE UP Dragon's Fist by Shinichi Ishihara, COOL BLEW According to Plan by Yasuyuki Maekawa and Tetsuo Kanao and BURNING HEART My Passion is Burning by Kouhwi Takeda

I really want Grease to stay and help Team Build regardless of no upgrade. I hate to have Sawatari die on us.

All of that sounds WAY too good to be true... So I'm calling foul.While
hoping against hope in my heart of hearts.

There's no way that's legit at all. Insert songs are never 'rumoured' if they're real - they're either announced, or just dropped on us.

So far Build lacks any insert songs in series just like Ghost. Ex-Aid has lots of inserts songs. I think the reason why Build not yet has any insert songs because Toei want to save budgets.

You know, with the buttload of toys this show has it really doesn't make sense for them to not give Grease and upgrade.

from a story and a merch standpoint, i dont think he's going to survive in this series because the riders are more powerful than him, he's just not going to keep up with them especially with the other riders getting powerups.

it's nothing against the actor, i just think it's getting tiring of seeing an evil rider joining the good side, it's been this way since gaim.

there has to be a change in the formula when it comes to evil joining the good side, it's just too easy, it's getting boring from doing it so many times.

not going to spoil anything or what, but if you follow the actors on Instagram, Takeda Kouhei is still around, and is ALWAYS in Sento and Banjo's actors vids.
So he won't die for now.