For the "use with", Yes and no. You don't really need the nexus one, it's already on the Workshop. It's set as a requirement :P.

As for what it does, it gives an item that if you use it, disables the stat nerf Asura gives, but only during the first Cultivation tier. Asura halves your stats, this one doubles them.
With some skills, early game is * impossible with Asura in Chaos Mode. It's still doable with ranged ones and playing well, but melee ones are way too hard for my liking.
For anything lower than Chaos it's not really a "requirement". But you can obviously use it if you want to make early game easier.

What does this do? And "use with" means needs https://www.nexusmods.com/taleofimmortal/mods/21 ?