If you’re aiming to get geared up in preparation for the Pandemonium raids, you’ll want to unlock the Zodiark and Hydaelyn Extreme Trials. These trials are much tougher versions of the story trials you’ve already completed, and will require you and your party to bring their A-game to succeed. The rewards are worth the effort, however, as you will obtain item level 570 weapons from completion of these trials, as well as a chance at a rare mount.
Participating in these Extreme Trials requires two things — unlocking them by speaking to the Wandering Minstrel after completion of the quest Endwalker, and an item level average of 560. You can obtain higher item levels by acquiring Tomestone gear or equipping gear drops from the level 90 dungeons, Smileton and Stigma Dreamscape.
To unlock the Extreme Trials, head to Old Sharlayan once you’ve viewed the Endwalker credits. In the Scholar’s Harbor, the Wandering Minstrel will be leaning against a wall. Speak to him, and regale him with stories of your fights against the primals. He will sing a song, and you will have unlocked The Minstrel’s Ballad: Zodiark’s Fall and Hydaelyn’s Call. You can queue for these Trials by heading to the High-end Duty tab of your Duty Finder.