The Floating Palace

Head to Mt. Tianheng: Your first stop is Mt. Tianheng. If you've already unlocked the Waypoint southeast of it, use that. Otherwise, just make your way to the highest point near the Jade Chamber. Once you're at the summit, you'll trigger a cutscene.

Find a Way Up: After the scene, Paimon will suggest finding a way to reach the Jade Chamber. Look for a mysterious four-leaf clover object. Switch to any character with the Anemo element and use their Elemental Skill on it. This will create a wind current that you can use to lift yourself into the air.

Glide Through Accelerators: Once you're airborne, you'll see white accelerator rings. Glide through them – each one will propel you further. You'll land on small jade platforms, and after the last one, another scene will play. Paimon will then get the idea to use the Guizhong Ballista.

Head to the Guizhong Ballista: Before you move on, make sure to open the chest you find near the platform. Then, head northwest towards the Guizhong Ballista. As you get closer, you'll encounter some Millelith Guards who think you're trespassing.

Fight the Millelith: You'll have to fight them off. The first group has three Millelith Soldiers. They're not too tough, but watch out for their three-hit combo if they're rallied by a Sergeant. After you defeat them, a second group will appear, this time with three Millelith Soldiers and one Millelith Sergeant. The Sergeants are a bit tougher and can counter-attack. A good strategy here is to use Hydro and Cryo to freeze them, then switch to Electro or Pyro to finish them off quickly. You'll face one more group, identical to the second. Use the same strategy to defeat them.