Dragon Ball Super added several cosmic elements to the world of Akira Toriyama's popular franchise. In Dragon Ball Z, the Supreme Kais were seen as the ultimate lifeforms in the galaxy, but Super debuted the Gods of Destruction, divine beings as powerful as they are petty. These two groups of incredibly powerful beings are also connected in a critical way.
Though they may have incredibly different tasks in the universe, the Supreme Kais and the Gods of Destruction can't live without the other for one important reason. Here are the roles that each plays in the Dragon Ball universe and how they connect.
Supreme Kais vs. Gods of Destruction
The Supreme Kais are beings that are born divine and have an incredible amount of innate power. Even more powerful than the normal Kais, the Supreme Kais watch over both the supernatural Other World and the world of the living. Their jobs are to protect these worlds at all costs. There are usually three Supreme Kais per universe, though only two of them will be active at a time with one on standby.
Their counterparts are the Gods of Destruction, who, as their names would suggest, destroy those they deem as a major threat to the development of their universe at large. Those primed for destruction can be people, species and even entire planets. Unlike the Kais, however, the Gods of Destruction come in a variety of forms and fashions. This is because they are not born divine and are instead chosen to become Gods of Destruction. They are also far more powerful than the Supreme Kais, though their comparatively petty nature means that they're far less likely to help out with the affairs of mere mortals.
How Supreme Kais and Gods of Destruction Are Linked
Despite, or perhaps due to their vastly different roles, the Supreme Kais and the Gods of Destruction are intrinsically linked via their very lives. If all of the Supreme Kais in a universe are killed, that universe's Gods of Destruction will automatically die, as well. However, if only one Supreme Kai dies, the God of Destruction can live on. On the other hand, their God of Destruction dying would doom every last one of a universe's Kais.
The reason for this symbiotic mortality is a matter of balance. The loss of the Supreme Kais or a God of Destruction would leave an unbalanced power vacuum in the universe, hence the auto-death. This shows how, in the world of Dragon Ball Super, no one is powerful enough to escape the possibility of death. After all, if even gods can die, then mere mortals certainly have their work cut out for them in the realm of survival.
This is shown in mortals being trained by and even fighting with these gods, as well as Supreme Kais many times coming to blows or even coming close to death. Thankfully for anyone unlucky enough to kick the bucket, resurrection is always just one wish from the Dragon Balls away, be they gods or mortals.