Kamen Riders sometimes possess a stronger or alternate version of their Final Form or gain a new final form when they lose their original one.
Fourze and Wizard notably evolved their final forms twice over, first in their Summer Movie, and again in the Movie War film with their successor, making them the only Riders with Extra Extra Final Forms in addition to Kuuga's S.I.C. Hero Saga-exclusive Super Rising Ultimate Form. Kiva, Decade, and Double also have two Extra Final Forms, but they are seperate from each other.
There are a few rare cases where secondary Riders have achieved Extra Final Forms of their own, such as Mach Chaser and Cross-Z Evol.