Quantum Riddler

a Sphinx attacks — 144 cards in the game can cause this (Quantum Riddler is one).

1. The Ur-Sphinx — When Quantum Riddler attacks, The Ur-Sphinx mills a card

a Sphinx enters the battlefield — 149 cards in the game can cause this (Quantum Riddler is one).

1. Unesh, Criosphinx Sovereign — When Quantum Riddler enters, Unesh, Criosphinx Sovereign triggers

a card is drawn — 3,815 cards in the game can cause this (Quantum Riddler is one).

1. Temmet, Naktamun's Will — When Quantum Riddler makes a player draw a card, Temmet, Naktamun's Will gives +1/+1
2. Niv-Mizzet, Parun — When Quantum Riddler makes a player draw a card, Niv-Mizzet, Parun deals 1 damage
3. Aether Syphon — When Quantum Riddler makes a player draw a card, Aether Syphon mills a card
4. The Locust God — When Quantum Riddler makes a player draw a card, The Locust God makes a token
5. Starving Revenant — When Quantum Riddler makes a player draw a card, Starving Revenant makes each opponent lose 1 life
6. Diviner's Wand — When Quantum Riddler makes a player draw a card, Diviner's Wand gets +1/+1
7. Ominous Seas — When Quantum Riddler makes a player draw a card, Ominous Seas puts a foreshadow counter on itself
8. Dream Trawler — When Quantum Riddler makes a player draw a card, Dream Trawler gets +1/+0
9. Scrawling Crawler — When Scrawling Crawler makes a player draw a card, Quantum Riddler draws you that many plus 1 cards
10. Iron Man, Armored Avenger — When Quantum Riddler makes a player draw a card, Iron Man, Armored Avenger puts a counter on a creature

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

anything attacks — 17,934 cards in the game can cause this (Quantum Riddler is one).

When Quantum Riddler attacks:

1. Far Fortune, End Boss — deals 1 damage
2. Grim Javelineer — gives +1/+0
3. Invisible Woman — triggers
4. Caesar, Legion's Emperor — sacrifices a creature
5. Guide of Souls — triggers
6. Campsite Cuisine — sacrifices a Food
7. Gossip's Talent — triggers
8. Banon, the Returners' Leader — draws and discards
9. Toph, Earthbending Master — puts a counter on a permanent
10. Three Dog, Galaxy News DJ — sacrifices an Aura

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

a creature attacks — 17,934 cards in the game can cause this (Quantum Riddler is one).

When Quantum Riddler attacks:

1. Adaptive Omnitool — searches a library
2. Anthem of Rakdos — gives +2/+0
3. Kindred Discovery — draws you 1 card
4. Invasion of New Capenna // Holy Frazzle-Cannon — puts counters on a permanent
5. Chorale of the Void — brings a card back
6. Jolene, Plundering Pugilist — makes a token
7. Saw — sacrifices a creature
8. Gisa's Favorite Shovel — makes an opponent sacrifice a creature
9. Ultima Weapon — kills a creature an opponent controls
10. Total War — kills a creature

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

a creature blocks — 17,934 cards in the game can cause this (Quantum Riddler is one).

When Quantum Riddler blocks:

1. Mage Hunters' Onslaught — makes a player lose 1 life
2. Carnage Gladiator — makes a player lose 1 life
3. Barrow-Blade — strips abilities
4. Heat of Battle — deals 1 damage
5. Battle Strain — deals 1 damage
6. Favor of the Woods — gains you 3 life
7. Tide of War — sacrifices a creature
8. Dead-Iron Sledge — kills a creature
9. Dwindle — kills a creature
10. Shield of the Righteous — triggers

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

a nontoken creature attacks — 17,934 cards in the game can cause this (Quantum Riddler is one).

When Quantum Riddler attacks:

1. Mardu Ascendancy — makes a token
2. Basri Ket — makes a token
3. Militia's Pride — makes a token

a creature deals combat damage — 17,934 cards in the game can cause this (Quantum Riddler is one).

1. Locutus of Borg — When Quantum Riddler deals combat damage, Locutus of Borg makes a token

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

a creature enters the battlefield — 19,800 cards in the game can cause this.

When Quantum Riddler:

1. Slash, Reptile Rampager — enters, Slash, Reptile Rampager deals 2 damage
2. Ray Fillet, Wave Warrior — enters, Ray Fillet, Wave Warrior puts a counter on itself
3. The Neutrinos — enters, The Neutrinos gets +1/+0
4. Wingnut, Bat on the Belfry — enters, Wingnut, Bat on the Belfry grants flying, haste and menace
5. Pirated Copy — enters because Pirated Copy copies it, its ability triggers again
6. Leitmotif Composer — enters because Leitmotif Composer copies it, its ability triggers again
7. Three Steps Ahead — enters because Three Steps Ahead copies it, its ability triggers again
8. Copycrook — enters because Copycrook copies it, its ability triggers again
9. Season of Weaving — enters because Season of Weaving copies it, its ability triggers again
10. Waxen Shapethief — enters because Waxen Shapethief copies it, its ability triggers again
11. Sublime Epiphany — enters because Sublime Epiphany copies it, its ability triggers again
12. Here Comes a New Hero! — enters because Here Comes a New Hero! copies it, its ability triggers again
13. Test of Priorities — enters thanks to Test of Priorities, it draws you 1 card
14. Anticausal Vestige — enters thanks to Anticausal Vestige, it draws you 1 card
15. Aetherstorm Roc — enters, Aetherstorm Roc puts a counter on a permanent you control
16. Raphael, Most Attitude — enters, Raphael, Most Attitude exiles a card from your library

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

anything enters the battlefield — 26,499 cards in the game can cause this (Quantum Riddler is one).

1. Prowl, Stoic Strategist // Prowl, Pursuit Vehicle — When Quantum Riddler enters, Prowl, Stoic Strategist // Prowl, Pursuit Vehicle puts a +1/+1 counter on itself

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