Demon Keefe, as the boss on the surface of Kamen Rider Revive, now has a strange form, but it seems that it needs further evolution, let's talk about Kiefe's evolution route
The first evolution occurred when phoenix's people were besieging the base of the outlaws, when it absorbed the remnants of the downtaken planarians and outlaws stage 3 and sabertooth tiger outlaws stage 3, at which point it was able to control the base ship to attack the city.
The second evolution took place in the base of Phoenix, after absorbing the residue of the defeated outlaws many times, its activity was further enhanced, and then it was also an evolved tentacle to actively attack and devour humans, and its shell was also easily able to resist the attack of the shell.
The third time was when Kamen Rider Revive's Revive form appeared, and at this time, after he devoured Brother Octopus, he also successfully pictured the shackles of Kiev's coffin, evolving into a strange form.
These are Kiefe's three current evolutions, and the subsequent evolution should be related to the demons of the Igarashi siblings, and it is very likely that the demons that devoured them achieved the final evolution.