Card

Linvala, Keeper of Silence

Mana cost {2}{W}{W}

Flying Activated abilities of creatures your opponents control can't be activated.

Part of 7 known combos, 2 of them two-card. 3 official rulings.

Bracket

B1 Exhibition — Not in the same deck as its two-card combo partners: Living Plane, Nature's Revolt
B2 Core — Not in the same deck as its two-card combo partners: Living Plane, Nature's Revolt
B3 Upgraded — Not in the same deck as its early two-card combo partners: Living Plane, Nature's Revolt
B4 Optimized — allowed: No restriction beyond the banned list
B5 cEDH — allowed: No restriction beyond the banned list

Two-card combo with Living Plane, Nature's Revolt (early with Living Plane, Nature's Revolt)

Bracket: Lotus Vault analysis, with Commander Spellbook flags

7 known combos, 2 of them two-card.

Linvala, Keeper of Silence + Living Plane
Produces: Opponents can't tap lands for mana, Lock, Mass Land Denial
View on Commander Spellbook
Linvala, Keeper of Silence + Nature's Revolt
Produces: Lock, Mass Land Denial, Opponents can't tap lands for mana
View on Commander Spellbook
Linvala, Keeper of Silence + Kormus Bell + Urborg, Tomb of Yawgmoth
Produces: Opponents can't tap lands for mana, Lock, Mass Land Denial
View on Commander Spellbook

2017-03-14 · Wizards of the Coast
No abilities of creatures your opponents control can be activated, including mana abilities.
2017-03-14 · Wizards of the Coast
Linvala’s last ability affects only creatures on the battlefield. Activated abilities that work in other zones (such as bloodrush or unearth) can still be activated. Triggered abilities (starting with “when,” “whenever,” or “at”) are unaffected.
2016-06-08 · Wizards of the Coast
Activated abilities contain a colon. They’re generally written “[Cost]: [Effect].” Some keywords are activated abilities and will have colons in their reminder text.

Rulings: Scryfall · Wizards of the Coast