[Kiwami]

I was about to say the same thing, but with one additional reason: Godai always needs to learn what his new forms actually do before he's able to properly utilize them.

With Dragon Form he knew it was faster than Mighty, but he couldn’t beat the Gorongi until Sakurako told him that this form specializes on rod weapons. This will continue with every form aside from the super ones and I love it.

Because we as an audience usually accept it if a Kamen Rider can properly handle a new form the very first time he tries it, but it doesn’t really make sense, that's why I love Kuuga's form changes the most.