The Kaio-Ken doesn't always get the respect it deserves in DBZ, but it's arguably a cooler transformation than Super Saiyan with even better fights.

Only Goku has mastered Kaioken, using up to x20 but never combining it with Super Saiyan. Combining Kaioken with SSJ is risky due to the emotional stress of SSJ affecting ki control. Kaioken is ...

If you separate the two transformation categories, then there’s still room to grow within the traditional Super Saiyan line without god powers. There’s at least a place where Goku can name a ...