The Memoirs of Lady Trent series is a massive deep-dive into dragon folklore disguised as naturalist expeditions, but honestly, my favorite for pure myth-weaving is 'Driftwood'. It's this weird, dying multiverse setting where the last survivors from different worlds cling to fragments of their own collapsing realities and gods. The whole thing feels like listening to a hundred different creation myths in their final, fading breaths. The gods in that book are these desperate, forgotten, and sometimes spiteful entities that haunt the edges of stories, and the protagonist, Last, is basically a folklorist by accident, collecting tales of worlds that are about to blink out.
Her Onyx Court series, starting with 'Midnight Never Come', also plays heavily with Elizabethan faerie lore, but inverts it by grounding the fae court in the political underbelly of historical London. It’s less about retelling known myths and more about constructing a secret history where folklore is a living, dangerous bureaucracy. I've seen some readers find the first book a slower political build, but the way Brennan layers the glamour and rules of the fae over real historical events scratches a very specific itch for me.