ULTRACRAFT is a passthrough mod in the SkyCraft mould, but pointed the other way: Minecraft is the host world, and ULTRAKILL runs alongside it through a BepInEx 5 plugin called UltraBridge. Press F8 to switch between Steve and V1, ULTRAKILL’s robot, and take its movement and guns into a block world.
Its commits credit Claude Opus 5.5 as co-author. It’s Windows only and needs ULTRAKILL on Steam. The release comes as a Modrinth .mrpack or CurseForge zip that bundles Fabric API, Sodium and Essential, or you can install it on Fabric 1.21.11 by hand. With more than 5,600 release downloads by 9 October 2026, it’s one of the most-downloaded mashups since the first wave.
Lineage
Built on: Fabric.
See the whole family tree.