
Sync (Forge) is an unofficial reimplementation of the Sync mod, that was originally developed by iChun.
This particular fork is different because it works more stable with curios, and other mods like Zoe Isn't Cyberpunk, or any other mods that change player in more ways than just inventory or NBT. This mod will get deprecated when Sync (Forge) updates and officially fixes curios, and other incompatibilities.
As for the brief description of the mod, I think the original one says it all:
This mod provides clones, or as we like to call it, "shells". These shells are basically new individuals, with their own inventory, experience level, and even gamemode. However, they lack a mind that would control them. That's where the player comes in. Each shell is biometrically tied to the player whose sample was used to create it, and allows the player to "sync" their mind with it, essentially creating multiple player instances.




shell constructor and place it down.right-click the thing. ⚠️WARNING: this action will kill you! In order to create a shell with full health, the constructor must absorb 20HP (40 for Hardcore players). If you don't want to die, you can eat a golden apple to increase your maximum health, or you can hold a totem of undying during the process (which is the only option for Hardcore players).treadmill next to it (it should touch any side of any part of the shell constructor) and lure a pig or a wolf to its center to start generating piggawatts. You should end up with something like this:
P.S. - You don't really need a comparator, it's here just to demonstrate that you can determine progress of the shell construction process via strength of the comparator output.shell storage and place it down.redstone power.walk into it.menu that displays your shells: 
Select the shell you want to transfer your mind into, and enjoy the process!You can color-code shells stored in shell storages. Just right-click a shell storage with dye.
Syncing works cross dimensional, and should support custom dimensions.
If you die while using a shell, you'll be immediately synced with your original body (if you still have one; otherwise your mind will be transferred to a random shell).
Death of a shell doesn't increase your death counter.
Shell can be equipped (or unequipped) with armor, tools, etc. via hoppers connected to a corresponding shell container.
Shell storage should be constantly supplied with power in order to keep stored shell alive.
shellStorageAcceptsRedstone option is set to true.It's possible to measure a shell container's state with a comparator.
Shell storage and shell constructor are pretty fragile, so don't try to mine them without silk touch enchantment.
This project is licensed under the MIT License