Countermand

a card is milled — 772 cards in the game can cause this (Countermand is one).

1. Lo and Li, Royal Advisors — When a permanent makes a player mill a card thanks to Countermand, Lo and Li, Royal Advisors puts a counter on an Advisor

an instant is cast — 3,931 cards in the game can cause this (Countermand is one).

When Countermand is cast:

1. Lunar Mystic — draws you 1 card
2. Ojer Pakpatiq, Deepest Epoch // Temple of Cyclical Time — grants rebound
3. Repeated Reverberation — copies an ability
4. Riku of Two Reflections — copies a spell
5. Sword of Wealth and Power — copies a spell
6. Lilah, Undefeated Slickshot — gets +1/+1
7. Gale, Waterdeep Prodigy — brings a card back
8. Harness the Storm — brings a card back
9. In the Eye of Chaos — counters a spell
10. Niblis of Frost — taps a creature an opponent controls

427 other cards care about it too. These are the ones with the most connections.

a card in a graveyard — 7,589 cards in the game can cause this (Countermand is one).

1. Fire Nation Salvagers — Countermand puts cards into the graveyard that Fire Nation Salvagers can bring back
2. Bloodbond March — Countermand puts cards into the graveyard that Bloodbond March can bring back
3. Heart-Shaped Herb — Countermand puts cards into the graveyard that Heart-Shaped Herb can bring back
4. Enlightened Confidant — Countermand puts cards into the graveyard that Enlightened Confidant can bring back
5. Tergrid, God of Fright // Tergrid's Lantern — Countermand puts cards into the graveyard that Tergrid, God of Fright // Tergrid's Lantern can bring back
6. Grazing Kelpie — Countermand puts cards into the graveyard that Grazing Kelpie can bring back
7. Dauthi Voidwalker — Cards Countermand would put into an opponent's graveyard are exiled by Dauthi Voidwalker instead, and it can play from among them
8. Spurnmage Advocate — Countermand puts cards into the graveyard that Spurnmage Advocate can bring back
9. Endurance — Countermand puts cards into the graveyard that Endurance can bring back
10. Merfolk Windrobber — Countermand fills an opponent's graveyard toward the 8 or more cards Merfolk Windrobber needs

434 other cards care about it too. These are the ones with the most connections.

anything goes to a graveyard — 7,589 cards in the game can cause this (Countermand is one).

When a card hits the graveyard thanks to Countermand:

1. The Haunt of Hightower — puts a +1/+1 counter on itself
2. Duskmantle Guildmage — makes each opponent lose 1 life
3. Vulturous Zombie — puts a +1/+1 counter on itself
4. Bloodchief Ascension — makes each opponent lose 2 life
5. Compost — draws you 1 card
6. Planar Void — hits a graveyard

5 other cards care about it too. These are the ones with the most connections.

anything is cast — 31,128 cards in the game can cause this (Countermand is one).

When Countermand is cast:

1. Windrider Wizard — draws you 1 card
2. Relic Amulet — puts a charge counter on itself
3. Rockslide Sorcerer — deals 1 damage
4. Umara Wizard // Umara Skyfalls — grants flying
5. Alania, Divergent Storm — makes an opponent draw 1 card
6. Umara Mystic — gets +2/+0
7. Master of Winds — triggers

5 other cards care about it too. These are the ones with the most connections.