Izano Kurosawa

The three types are charged differently. The neutral one is fairly simple- put in any accepted Rustbound Magic item or a temporal gear in order to charge it. The Dark Nexus can only be charged by bringing creatures other than players next to it to drain their life energy. And a Light Nexus recharges and gains essence overtime, but only when exposed to sunlight(Meaning it only charges during the day without a roof). I have had a few friends that tried to charge a Light Nexus indoors, and I had to show them the right way because they complained how the Light Nexus wasn't charging. It tells you in the Guidebook you can craft with a fiber and rusty dust how each nexus works and how to upgrade them- along with any rituals and world magic stuff.

I don't know if you can use extinguished torches, but you can make any Mana Torch easily by putting a Mana Stone(One Stone(any type) and one Rusty Dust) into the corresponding nexus, taking 3 essence to create one torch based on the Nexus' type(ie. Light Nexus makes Light Mana Torch).