Description
Kylshiem is a mod that adds a new dimension, a new material with which you can make tools, weapons, and armor, a couple blocks, a couple mobs, and most importantly, 3 bosses.
Access to the dimension is available after defeating the ender dragon an travelling to the outer islands, where you'll be able to find Discarded Automotons. Killing them gets you broken gears, which can be used to craft the replica world engine key. using the replica key takes you to The Gateway, in which you'll find Gatewraiths. Kill a Gatewraith for an Orb of Void to finish travelling to Kylshiem. In Kylshiem you'll find automotons and drones, which can be killed for flawless gears and gold nuggets, whhich are used to craft the world engine key which is needed to get back to the overworld. In Kylshiem there will be ruins everywhere with Frigid Brass making up a portion of said ruins. Using frigid brass you can make the boss altar, and I'll let you figure it out from there.
JEI is heavily recommended.