Art Shift: Aside from the multiple lapses into chibi style, the art has more than once switched abruptly to a very shojo style in parody of particularly shojo-esque moments — notably, the use of "Sid-Vision 5000".
Curse: The original premise was that each one of the group had some curse on them that they've been trying to break by finding the Sylphe's artifacts. But it turned out that only two of them actually are cursed. Kit was turned humanoid when she accidentally hosted the Sylphe, Nigel is actually a golem commanded to find the Sylphe and he made up his backstory as an excuse for following Kit around, and Zeph was a spy working for Sigurd.
Lord of the Dying Light: No need to get up. Oh wait, that's right, you can't. ...Did you say something? Sid: He was going to ask you what your grand scheme was! So we can... bask in the glow of your evil genius! Lord of the Dying Light: No more explaining.
Failure Knight: Nigel is a war golem who was created to protect the Alchemist. When he failed in his mission, the Alchemist ordered him to find and help Sylphe. He follows Kit for that reason — though since golems are bound to obey the word of their masters, he may not have much choice in the matter.
Functional Magic: Fey and other creatures of nature tap into "the Song" (Force Magic) directly. Humans, elves, and other mortal races must employ "the Rule" (Rule Magic) a system of formulas and spells. Most of the main cast are also chasing after artifacts (Device Magic) left behind by a strange being called Sylphe when she rebelled against those who wanted to use her in a war.
One of the more unusual things about Kit is that she can use the Song, it turns out to be because she ate the Sylphe, and Nigel is a golem who can use the Song as well.
God in Human Form: Sigurd's plan. Using a number of components (several involving our heroes) he planted a piece of a god into one of his golems. She wasn't happy about it.
Golem: Quite a few of them were used in this one giant war. The Sylphe was apparently one, and Nigel is a golem that was commanded to find her. Kit is some mix of golem and fox that resulted when the Sylphe turned herself into a small shiny object that some hapless woodland critter mistook for an egg.
Overly Long Name: Prince Sidney Theodorus Cassian Merriweather Findain VIII. Mercifully, he only ever goes by Sid in the actual comic. His brother's name is slightly shorter — Dorian Norwood Anson Findain VI.