mtg nightmare commander deck Magic: The Gathering Duskmourn: House of Horror Bundle that player loses 2 life and you draw a card. Chainer, Nightmare Adept - Graveyard

This intimidating, gargantuan horror does an excellent job of showing you just how dangerously powerful Seymour is

Tutoring for that legendary creature as and when you need it

This is a fun three mana four equip (usually, note the tribal synergies for Commanders with those tribes) which keeps it at the 4 spot on this countdown

5 Scourglass A one-sided board wipe that almost always works in your favor, Scourglass is a unique artifact that decimates the battlefield if not answered by your next turn

As for Promising Stairs, you want it unlocked as soon as possible so you can control your top deck and win the game once you have eight different Rooms unlocked