Known as the Highest Authority of the World Government, the Gorosei are the rulers of the entire world, and have complete control over all government affiliated organizations; such as the police, the ten Cipher Pol units, and even the Marines; as they are all completely subservient to their commands. Even the orders of the fleet admiral of the Marines can be vetoed by their decisions. They can declare a Buster Call attack on any island that they deem a threat and can pass that authority onto lower World Government ranking agents. They can revoke a Shichibukai’s title, if they decide that he/she is not living up to their duties as a Shichibukai. So far, none of their names have been revealed.
They have shown to have at least a basic knowledge of the occurrences of the Void Century, according to their shocked reactions to Professor Clover’s statements. They have shown a paranoid fear of someone reviving the ancient weapons, to the point of forbidding its research and ordering the utter destruction of the entire country of Ohara, though given what is known of the Void Century, they may simply be using that as an excuse in order to prevent information they do not want leaked to the public from getting out.
Political powers aside, it is currently unknown how strong each one of the Gorosei are. However, due to their clear muscles and scars, and that one of them is wielding a sword, it would appear that they have some battle experience and fighting capabilities. Also in Robin’s flashback, it appears that their appearances haven’t been altered at least, despite it being taking place twenty two years ago.
This has given rise to a lot of theories about the possibility that they are immortal or at least have an incredibly long lifespan that could potentially date back to even the Void Century. People who believe in this theory usually see the Gorosei as the people who were there when the World Government formed and took control of the world, and they have likely been in command of the organisation for all these centuries. Because of this, we could hypothesize that they will serve as the final antagonist of the series.