The sky module allows the player to manually spawn in sky islands with exclusive content.
In order to spawn sky islands, the player has to find or create a sky portal. Sky portals consist of a 5×5 blocks frame of Glowstone filled with water source blocks. Sky portals sometimes generate naturally underground in generated structures.
To trigger a sky portal, a player must drop a Bottle o' Enchanting in the middle of the portal. The item will be consumed and 15 to 20 sky islands will spawn.
Sky islands are made of white wool and exist in four different sizes. The bigger an island is, the lower it will spawn. Big islands have a chance of spawning with Skyroot trees and lakes.
Harpies are flying mobs with a bird's face. They will try to charge to the player and to throw hurtful feathers at him. They can drop Blueberries.
Aetherians are blue-skinned mobs with sea lanterns as their head. They are hostile and come in two variants: Melee and Ranged. They will either fight with a bow or a stardust sword.
Boss: the Celestial
The Celestial is a boss that can be spawned in the Sky. It has one thousand health points, making it the entity with the most life in the entire game.
The Celestial can be spawned by dropping the four sky artefacts on the same block. They will be consumed and the Celestial will appear.
The Celestial uses random attacks every fifteen seconds. The first attack is to spawn a small explosion at the position of the player. The explosion will not destroy any blocks but can deal severe damage. The second attack will grow vines on the player, inflicting a wither effect. When the player is too close to the Celestial, he will receive a short levitation effect, preventing him from dealing important melee damage to the boss.
The Celestial is immune to most negative status effects, such as Poison, Wither and Levitation. He is also immune to fire damage, cactus damage and fall damage, making it very hard to farm.
If the Celestial falls off the Sky islands, he will despawn. It is therefore recommended to build a platform under the fight region or to keep him in an arena.