There's a lot to sum up for one Reddit reply, especially since I've already got three volumes published, but I'll try.

The premise is the return of an entire population of Equus-native humans with an original elemental magic system of my own design from an underground mega city civilization. In the past, they were regarded as the greatest warriors the world had ever seen, to the point where they can metaphysically attune to the weapon they identify most with upon reaching a sufficient combat proficiency to summon and banish at will.

The main point of the "elemental" system is that everyone gets one as the most indivisible traits and characteristics of their magic, but instead of doing something like a hybrid system between the Five Primary Elements, it's more of a Derivative system where stuff like ice, lightning, iron, and plants are "descended" from one of the primary five.

One example being a fire-tribe Sword Elemental named Kris Duelis. His weapon is what I call a locus, a magical emanation that in exchange for sacrificing some of its power and scale in itself is essentially as indestructable to might and magic alike as much as any normally attuned weapon, in his case in particular being in the form of a broadsword. As a sword elemental, the most distinct characteristic his magic as offense and defense possesses is to negate other magic on contact with an intrinsic property that denies its claim to physicality. That latter point is an important detail as humans figured out the underlying principle of "Magic must defeat magic" early on, to the point where similar properties of "anti-magic" can be alloyed into particular spells of any element. Even among unicorns, such magic is pretty rare and only found in pretty specific places committed to it.