Lavinia, Azorius Renegade

Bracket

• B1 Exhibition — Not in the same deck as its two-card combo partners: Knowledge Pool, Omen Machine, Eye of the Storm, Possibility Storm
• B2 Core — Not in the same deck as its two-card combo partners: Knowledge Pool, Omen Machine, Eye of the Storm, Possibility Storm
• B3 Upgraded — Not in the same deck as its early two-card combo partners: Knowledge Pool, Omen Machine, Eye of the Storm, Possibility Storm
• B4 Optimized — allowed: No restriction beyond the banned list
• B5 cEDH — allowed: No restriction beyond the banned list

Why

• Two-card combo with Knowledge Pool, Omen Machine, Eye of the Storm, Possibility Storm (early with Knowledge Pool, Omen Machine, Eye of the Storm, Possibility Storm)

How Lotus Vault estimates a bracket

Bracket: Lotus Vault analysis, with Commander Spellbook flags

Combos

4 known combos, 4 of them two-card.

• Lavinia, Azorius Renegade + Knowledge Pool
  Produces: Counter all spells opponents cast that are created by Knowledge Pool, Exile all spells players cast from their hands, Lock
  View on Commander Spellbook
• Lavinia, Azorius Renegade + Omen Machine
  Produces: All spells opponents cast using Omen Machine are countered, Players can't draw cards, Lock
  View on Commander Spellbook
• Eye of the Storm + Lavinia, Azorius Renegade
  Produces: Opponents can't cast instants or sorceries, Lock
  View on Commander Spellbook

Combos: Commander Spellbook

Rulings

• 2021-03-19 · Wizards of the Coast
  Players may cast spells that they know Lavinia's second ability will counter. Any abilities that trigger when spells are cast will trigger and resolve if appropriate, and any effects that count spells cast will count those spells if appropriate.
• 2021-03-19 · Wizards of the Coast
  If an effect allows a player to cast a spell without paying its mana cost, that player can't choose to cast it and pay its mana cost unless another rule or effect allows that player to cast it that way. However, if that spell also has additional costs that require mana, paying that mana will stop Lavinia's last ability from triggering.
• 2021-03-19 · Wizards of the Coast
  For spells with {X} in their mana costs, use the value chosen for X to determine the spell's mana value.
• 2021-03-19 · Wizards of the Coast
  Effects that modify or replace the cost to cast a spell (such as flashback or casting a spell without paying its mana cost due to suspend) don't affect the spell's mana value, so they won't change whether Lavinia's first ability restricts that spell from being cast.

Rulings: Scryfall · Wizards of the Coast