Can't rematch Elite Four :(

[DARI]

The old man says there are no rematches yet. I already did some missions and got some legendaries. I don’t know what to do next. Any help would be appreciated

[A_Wild_Noob_Appeared]

You need to fight Arceus first. There’s a list of the requirements here

Collaborative Post Game Guide

This is a guide for all the post game events. Please contribute by adding onto it and correcting possible mistakes. Here’s a list of quests not done yet that anyone is welcome to write (this is not a comprehensive list, things will be missing): Perfection Lab in Metchi Town, Perfection Base Mewtwo, and other stuff I am most likely forgetting. 1st Quest- The Timeless

First Quest Guide

After you beat the E4, go back to the cave south of Amphrite city where you battled Mew. The timeless will …