Pestilence

Bracket

• B1 Exhibition — Not in the same deck as its two-card combo partners: Maha, Its Feathers Night, Smaug the Impenetrable
• B2 Core — Not in the same deck as its two-card combo partners: Maha, Its Feathers Night, Smaug the Impenetrable
• B3 Upgraded — Not in the same deck as its early two-card combo partner: Smaug the Impenetrable
• B4 Optimized — allowed: No restriction beyond the banned list
• B5 cEDH — allowed: No restriction beyond the banned list

Why

• Two-card combo with Maha, Its Feathers Night, Smaug the Impenetrable (early with Smaug the Impenetrable)

How Lotus Vault estimates a bracket

Bracket: Lotus Vault analysis, with Commander Spellbook flags

Combos

17 known combos, 2 of them two-card.

• Maha, Its Feathers Night + Pestilence
  Produces: Destroy all creatures opponents control during each turn
  View on Commander Spellbook
• Smaug the Impenetrable + Pestilence
  Produces: Near-infinite damage to all players, Near-infinite damage to creatures, Near-infinite artifact ETB
  View on Commander Spellbook
• Cacophodon + Rite of Passage + Pestilence
  Produces: Infinite damage, Near-infinite +1/+1 counters
  View on Commander Spellbook

Combos: Commander Spellbook

Rulings

• 2011-06-01 · Wizards of the Coast
  It will stay on the battlefield if there is a creature that is put into the graveyard during the end step. This is because this ability will not trigger at all if there is at least one creature on the battlefield as the end step begins.
• 2011-06-01 · Wizards of the Coast
  Note that "until end of turn" effects wear off after "at the beginning of the end step" triggered abilities, so an artifact that animates until end of turn can keep this on the battlefield.
• 2004-10-04 · Wizards of the Coast
  Each activation is considered a new damage effect. An activation can only be 1 point of damage.

Rulings: Scryfall · Wizards of the Coast