James Islington’s work is often compared to other high fantasy series such as Brandon Sanderson’s Mistborn, Robert Jordan’s Wheel of Time, and Ursula K. Le Guin’s Earthsea trilogy. In the “Meet the Author” section, Islington credits Mistborn as the work that inspired him to write his own novels. The Licanius Trilogy falls under the high fantasy genre, which is known for its use of alternative worlds and epic narrative scale, as well as tropes such as magic schools, forbidden powers, and mythical creatures. The Shadow of What Was Lost employs these traits in its palace setting and the royal line of Tel’Andras, as well as the Gifted schools, the banning or restriction of Augur and Gifted powers, and creatures like the sha’teth and dar’gaithin.

The series’s complex magic system falls under the category of “hard magic,” where the characters’ powers are precisely defined and function according to strict logical rules. (By contrast, narratives that rely on “soft magic” have no distinct rules and seek instead to provide a tone of wonder.) In The Licanius Trilogy, the Gifted wield their own “Essence,” a term denoting the energy in all living things. The Gifted can conjure this life force from within themselves and apply it to the physical world; it manifests in streams of light from their hands. The Augurs, on the other hand, use kan, an “external force” that allows them to manipulate Essence; Augurs can both heighten the effect of Essence on the physical world and tap into the non-physical realms of thoughts and time. The rigid mechanics of kan, such as its ability to store, draw, and absorb Essence, places the narrative in the category of “hard magic.”

The novel also includes time travel as part of its magic system, but the story differs from science fiction narratives, in which time travel is dependent on technology. However, one allusion to science fiction can be found in the concept of the Tenets that restrict the powers of the Gifted. These rules pay homage to Issac Asimov’s famous Three Laws of Robotics, which were introduced in the 1942 short story “Runaround” and later included in his 1950 collection, I, Robot. Asimov’s laws dictate that robots cannot actively harm humans or passively allow harm to come to them. They must also obey human orders that do not conflict with this rule, and they can protect themselves only when doing so does not bring harm to a human. Similarly, in The Shadow of What Was Lost, the original Four Tenets require the Gifted to obey the Administration and do nothing that would hurt or deceive non-Gifted. Only after Wirr’s revision as the new Northwarden are the Gifted freed of the mandate for obedience and permitted to use Essence for self-defense.