Ob Nixilis, Captive Kingpin

Bracket

• B1 Exhibition — Not in the same deck as its two-card combo partners: All Will Be One, Casey Jones, Back Alley Brute, Shalai and Hallar
• B2 Core — Not in the same deck as its two-card combo partners: All Will Be One, Casey Jones, Back Alley Brute, Shalai and Hallar
• B3 Upgraded — Not in the same deck as its early two-card combo partners: All Will Be One, Casey Jones, Back Alley Brute, Shalai and Hallar
• B4 Optimized — allowed: No restriction beyond the banned list
• B5 cEDH — allowed: No restriction beyond the banned list

Why

• Two-card combo with All Will Be One, Casey Jones, Back Alley Brute, Shalai and Hallar (early with All Will Be One, Casey Jones, Back Alley Brute, Shalai and Hallar)

How Lotus Vault estimates a bracket

Bracket: Lotus Vault analysis, with Commander Spellbook flags

Combos

22 known combos, 3 of them two-card.

• Ob Nixilis, Captive Kingpin + All Will Be One
  Produces: Exile your library, Infinite +1/+1 counters on a creature, Infinite damage
  View on Commander Spellbook
• Ob Nixilis, Captive Kingpin + Agatha's Soul Cauldron + Walking Ballista
  Produces: Exile your library, Infinite damage
  View on Commander Spellbook
• Ob Nixilis, Captive Kingpin + Prosper, Tome-Bound + Sensei's Divining Top + Reckless Fireweaver
  Produces: Near-infinite +1/+1 counters on a creature, Near-infinite damage, Near-infinite storm count
  View on Commander Spellbook

Combos: Commander Spellbook

Rulings

• 2023-05-12 · Wizards of the Coast
  Ob Nixilis's last ability looks at all combat damage dealt to an opponent in total to determine whether it triggers. For example, if three 1/1 creatures deal combat damage to an opponent, that player loses 3 life. Ob Nixilis's ability won't trigger.
• 2023-05-12 · Wizards of the Coast
  Playing the card exiled with Ob Nixilis follows the normal rules for playing that card. You must pay its costs, and you must follow all applicable timing rules. For example, if the card is a creature card, you can cast that card by paying its mana cost only during your main phase while the stack is empty.
• 2023-05-12 · Wizards of the Coast
  If you don't play the card, it will remain exiled.
• 2023-05-12 · Wizards of the Coast
  Unless an effect allows you to play additional lands that turn, you can play a land card exiled with Ob Nixilis only if you haven't played a land yet that turn.
• 2023-05-12 · Wizards of the Coast
  You may play the card exiled with Ob Nixilis even if Ob Nixilis leaves the battlefield or you lose control of it.
• 2023-05-12 · Wizards of the Coast
  Ob Nixilis's last ability will trigger if an opponent is dealt exactly 1 damage, pays exactly 1 life, or loses exactly 1 life some other way.

Rulings: Scryfall · Wizards of the Coast