The Kiokameha is an energy blast when the user uses a kioken then charges up a kamehameha the kioken's energy has to go into the kamehameha's energy ball. It does massive damage but, you knowlonger are in a kioken state. Goku almost used one aginst Vegeta but, he stayed with his kioken state. It is hard to control and there are only 3 known users. Trunks, Central Kai, and Goten. All of them used it during the majin wars. Trunks used it aginst Vampine. Goten aginst Ciraid. Central Kai used it aginst Babirdi.

P.S. Vampine and Ciraid are in Majin wars. I am still working on it's storyline...