Coined officially as the first Kamen Rider of the Heisei Era, Kamen Rider Kuuga, he shares a lot of similarities with Ichigo and Nigo - its like coming back to its roots of the Kamen Rider. This also paved the way on how the treatment should be for the next generation of riders - themed, human and with a lot of beautiful transformations and firepower! That's why Kuuga remains as one of the most memorable Hsieh riders to date, in my opinion. To add, he is one of the most number of power ups in a single show, you might think its decade but he only has 11. I won't consider Kamen Rider OOOs because its like changing hats.
