Lumo

Lumo is a essence that is best described as 'tempremental.' It is a unruly beast in and of itself, but is generally considered to be the 'Holy Good' essence because of its assosiation with banishing its lower row element, Skoto, or 'Darkness.' However it can be a weapon like any other Essence in and of itself, often taking the form of burning away rot, corruption, darkness, cold, and other such Essences with radiance based magics and abilities.
Many wielders of Lumo realize the dangers of it. It has a tendency to 'bounce' leading to most individuals who wield it being covered head to toe with Lumo reflecting armor, often giving the sterotype of a 'bright shiny paragon of justice'. In reality, this is to prevent themselves from being heavily scarred or burnt by their own magic, as Lumo is very rarely one to be contained easily, and can instantly escape many different types of containments.   It is also a essence which grants sight to unseen things, and senses that allow for one to see more than one should usually. A disease caused from Lumo is often referred to as 'Facination' where one stares too deeply into Lumo often leading to long term madness assosiated with purging things via its light similar to Pyromania.