The Hyperion Dirge is a new world quest available in Enkanomiya in Genshin Impact Version 2.4, available after you unlock the Evernight and Whitenight feature of Enkanomiya. Before starting this quest, make sure to set the time of day to “Evernight.”
Teleport to the waypoint located in the middle of Dainichi Mikoshi, and drop off from behind the building. You’ll come across an indent of the building guarded by a couple of fire torches and Ruin Guards. Light up the torches and defeat the Ruin Guards, and a small entry in the wall will appear.
Enter inside this hole, and you’ll see a spirit in front of three altars. This spirit is named Aberaku, and he tasks you with finding objects which contain his thoughts. These objects are located throughout Enkanomiya, one in The Narrows, The Evernight Temple, and The Serpent’s Heart.
The Narrows (Narrow Inquiry)
Head to this location at The Narrows. Here, you’ll see a group of Key Sigils. Unlock all of the Key Sigils. Aberaku will appear in front of you. Talk to him to begin a Time Trial Challenge where you’ll need to defeat three Primordial Bathysmal Vishaps in 30 seconds.
The Serpent’s Heart (Serpent’s Heart Inquiry)
The next subquest is at The Serpent’s Heart. To unlock this one, go to this location in The Serpent’s Heart. You’ll need to activate five sigils again to unlock a subquest. You’ll need to defeat some Abyss Mages here to complete the quest.
The Evernight Temple (Temple Inquiry)
The final subquest is at the Evernight Temple, found here. Like the last two times, you’ll need an assortment of Key Sigils to unlock the subquest. Complete some Rockhound and Rockhound Whelps to complete the quest.
Now that you have collected all three offerings, you can return to Aberaku at the Dainichi Mikoshi. Place the offerings on the altars, talk to Aberaku, and a phase gate will appear. Take that to a hidden room, where you’ll complete the quest after one last chat with Aberaku.