Stratospherical Expansion is a mod which completely overhauls the overworld generation to be made of sky islands. It also features completely reimagined vanilla biomes.
Requires Terrablender

!!! OUTDATED: Use the OG Stratospherical preset in Ecospherical Expansion instead of this mod. Note: That is only available in 1.20.x. Fabric/Forge!!!

There is a dimensional version of this mod which can be found under the files tab of this mod page. It separates this into another dimension instead of overriding the overworld. However, its features are more limited with overall simpler generation. To enter the dimensional version of this mod you must fly to Y420 in the overworld. To return you just fall into the void of the stratospheric dimension.

Discord: https://discord.gg/uWjKpHwq5W
This mod may be used in any modpack.**