Su Mubai stared dumbfounded at the Epic-level Treasure Chest in front of him. It took him a moment to realize that after upgrading to Epic-level, the chest could actually be stored in his backpack.

After checking the description of the chest, he understood that unlocking an Epic-level Treasure Chest didn't require a key.

[Epic-level Treasure Chest]

Locked status, requires 36 Space Crystals to unlock.