Nemesis

Nemesis is first introduced at the beginning of the second installment, "Water." After the battle in the Turquoise Archipelago, it berates the wendigoes that Jack Thunder and Buckthorn defeated for their incompetence. It soon finds out that the two are on their way to the Dark Carnival and makes a beeline for the Nursery Rhyme District.

In the third installment, "Darkness," Nemesis takes on the role of a puppetmaster. It infiltrates the Dark Carnival, manipulating The Great Strombolio into hiring it to help. It infects all of the Dark Carnival's patrons behind the Dark Champion's back. It is only when the team meets Shadow-Paws that Strombolio learns he's been tricked. In the ultimate battle, Shadow-Paws is able to free the carnival's patrons from Wendigo Possession by launching The Dark Fragment - Lethal Joke's laughing gas grenades at the stands, causing the patrons to start laughing and the wendigoes to evacuate their bodies. This eventually raises the level of Undifferentiated Anima in the room so much that Nemesis and the wendigoes are rendered helpless before they are banished.

Nemesis appears yet again in the fourth installment, "Earth." This time, it has infiltrated the grove of Ygdrassil by infecting a certain Sour Apple and corrupting him. When the team goes to look for Sour Apple, Nemesis attacks them in the form of a dryad-wendigo. Once it is defeated, it goes back to the grove to fetch Terra, but not before draining the Heartwood, the wendigo ward that protects the grove. When it catches up with the team again, it is inside a tunnel under Ygdrassil's roots where Terra is. It tries to pick the Earth Fragment up, but the combined Anima from all four Fragments sears its hands. Angered, it instead tries to throw a bolt of Null magic at Jack Thunder, but Snotter stops it just in time, burying it under a mountain of boulders. Once it gets out, it attacks the team again outside of Ygdrassil. When The Winter Solstice Spirit appears, the entire grove gets involved in defeating it and its army. Ultimately, after being trampled by Strombolio's Uninvited Parade, Snotter casts it into a pit and seals it in with vines. Nemesis and its minions are banished in short order.

In "Book 5: Fire," it corrupts the lava dragon Grimhide into attacking the crew. After its defeat, it quietly gives up. By the sixth installment, it has completely turned on its former goal, instead protecting the crew from another wendigo.

In the beginning, Nemesis is wholly focused on defeating Jack Thunder and stopping his crew from banishing the Heart of Darkness. As the series goes on, however, Nemesis starts to long for the life Jack Thunder and the other faeries in Altairus lead. It witnesses the team breaking bread with each other during the Winter Solstice at the end of Book 4, leading it to question itself. At the end of "Book 6: Light," it ultimately sacrifices itself to save Jack Thunder and company, willingly subscribing to being banished back to the Flipside.