The Cultist is one of the Gungeoneers in the game Enter the Gungeon, and is exclusively playable in co-op. They starts with Dart Gun, Friendship Cookie, and Number 2.
The Blacksmith refuses to give the Cultist the Bullet That Can Kill The Past; however, it is unnecessary to access The Cultist's past. Shooting them with The Gun That Can Kill The Past will access their past, whether or not the player has the Bullet. If the Cultist is shot with the Bullet that can Kill The Past, you will have to duel with the Cultist.