In addition to mythology, Siddell makes heavy use of alchemical themes; for example, the main character is named Antimony, after a toxic chemical element, and many pages feature artistic depictions of alchemical symbols. The symbol for antimony appears frequently in Gunnerkrigg Court: the character Antimony wears a necklace shaped like that symbol, the character Reynardine has the symbol imprinted on his wolf body, and the symbol is used to mark the end of a chapter.
Siddell incorporates mythological themes, particularly alchemical symbolism, into his work. For example, the main character's name is Antimony, referencing a toxic chemical element, and numerous pages feature depictions of alchemical symbols. The antimony symbol appears frequently in Gunnerkrigg Court: Antimony wears a necklace shaped like it, Reynardine has it imprinted on his wolf form, and it marks chapter endings.