Marvel's Spider-Man joined Magic: The Gathering in September, and Avatar: The Last Airbender launched November 21
It's very powerful in this way, especially given that its mutate trigger is potentially repeatable
While Sephiroth is super popular, the fact Nether Traitor is easily replaced in the deck by other cards that do a similar thing may limit the potential of this spike
Ashiok, Nightmare Muse Ashiok, Nightmare Weaver Braids, Arisen Nightmare Brisela, Voice of Nightmares Chainer, Nightmare Adept Chthonian Nightmare Collective Nightmare Elspeth's Nightmare Every Dream a Nightmare Hopeless Nightmare Hunted Nightmare Kaito, Bane of Nightmares Neva, Stalked by Nightmares Nightmare Nightmare Incursion Nightmare Lash Nightmare Shepherd Nightmare Sower Nightmare Unmaking Nightmare Void Nightmare's Thirst Nightmares and Daydreams Only Blood Ends Your Nightmares Persistent Nightmare Recurring Nightmare Sivriss, Nightmare Speaker Swimmer in Nightmares Taken by Nightmares The Ultimate Nightmare of Wizards of the Coast Customer Service Waking Nightmare Your Nightmares Are Delicious
Prize Card When youve beaten Ursula for the first time, youre allowed to open up the included promo prize pack
