Nucleus Mixins is an optional plugin for Minecraft 1.10.2 servers that attempts to provide features by hooking into the Minecraft
internals. You can get Nucleus Mixins from Ore.. They must be installed in the
/mods directory on SpongeForge servers in order to work.
Unforatunately, due to the nature of core mods, Nucleus Mixins may not work with heavily modded servers.
Mixins adds calls into the main Minecraft codebase to allow world pregeneration to operate more smoothly. These improvements have been integrated into Sponge for 1.11.2