Seen through 10 now, and is it just me of is Kuuga way too powerful? The green and purple form debuts both took out the Grongis in one hit.
This is actually part of the plot, and you will find out later that having too much power will cause some trouble for Godai.
If you also noticed, the green (Pegasus) form did not work for him right away. It actually made him lose the first battle.
That is one thing I found interesting with Kuuga's form changes. In the beginning they seemed to activate themselves randomly, which was not always a good thing, especially because Godai had no idea how to use them.
Like in Dragon Form's debut. It only activated because Godai wanted to jump high, but for the rest of the battle, he got his ass kicked because that from didn't have the strength of Mighty form.
If I remember correctly, they even addressed it as a problem that Godai could not switch back to Mighty Form again after going into Dragon Form.
It was not until later on that Godai could control his basic forms. With that also came his legendary "Chou Henshin!"
Then came the Rising Forms and everything went to **** again...