Void Totem (Forge) adds the Totem of Void Undying, which saves you from dying in the void. Hold it in your main or off hand, and if you fall out of the world you get teleported back to the surface. Handy in SkyBlock or when your elytra breaks over the End.
This build is for Forge and NeoForge, Minecraft 1.15.2 - 1.21.1. The config lets you blocklist dimensions, set the teleport height and use the totem from anywhere in your inventory. Running SkyBlock on a Minecraft server? Grab it with one click in the panel.