Just imagine if Jotaro and Josuke both got Requiem. Star Platinum and Crazy Diamond. Star Platinum could move through time and crazy offense abilities. And Crazy Diamond could reconstruct anything with offense abilities with Golden Wind. Woah!!!!
Literally resets everything to a state of 0. His stand stats are also 0 in everything. If GER stopped you from leaving your house, for example, you would just keep failing to leave your house since he will always return the situation back to how it began. I hope that makes a bit more sense.