Reduce to Dreams

an artifact leaves the battlefield — 1,680 cards in the game can cause this (Reduce to Dreams is one).

1. Sludge Strider — When an artifact leaves the battlefield thanks to Reduce to Dreams, Sludge Strider makes a player lose 1 life

a sorcery is cast — 3,720 cards in the game can cause this (Reduce to Dreams is one).

When Reduce to Dreams is cast:

1. Spellweaver Volute — copies a spell
2. Lilah, Undefeated Slickshot — gets +1/+1
3. Niblis of Frost — gets +1/+1
4. Primeval Bounty — puts 3 counters on a creature
5. Tetsuko Umezawa, Pursuer — gets +1/+1
6. Thor, God of Thunder — deals that spell's mana value damage
7. Krile Baldesion — brings a card back
8. Summon: Good King Mog XII — makes a token
9. Kykar, Wind's Fury — makes a token
10. Blood Funnel — sacrifices a creature

424 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 (Reduce to Dreams is one).

When Reduce to Dreams 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.