Quantum Riddler
Creature — Sphinx
Flying
When this creature enters, draw a card.
As long as you have one or fewer cards in hand, if you would draw one or more cards, you draw that many cards plus one instead.
Warp 
- CMC
- 5
- Mana cost
- Color identity
- U
- Rarity
- mythic
- Set
- Edge of Eternities Promos
- Price
- $40.28
- EDHREC rank
- #10247
Quantum Riddler lands as a repeatable card advantage engine that punishes opponents for ending their turns with untapped mana — the information asymmetry it creates is immediate and hard to play around. The cost is real: five mana is a significant ask, and Obeka, Brute Chronologist is the clearest home because she can skip the delayed downside entirely.
Best Commanders
Commanders with the highest synergy
Obeka, Brute Chronologist
Obeka, Brute Chronologist's ability to end the turn on demand lets Quantum Riddler's triggered drawback get blanked every time, turning a conditional engine into a clean, one-sided value machine.
Y'shtola Rhul
Y'shtola Rhul's end-step interaction rewards stacking triggered abilities, and Quantum Riddler fits directly into that gameplan by generating card advantage off the same timing window Y'shtola already wants to exploit.
Format Analysis
Where it lives, where it can’t
| Format | Verdict |
|---|---|
| commander | legal |
| legacy | legal |
| modern | legal |
| pioneer | legal |
| standard | legal |
| vintage | legal |
| pauper | not legal |
| oathbreaker | legal |
Commander is where Quantum Riddler earns its slot — 100-card singleton games go long enough that its incremental card advantage compounds, and multiplayer tables mean there are always opponents holding up mana to trigger it. In 1v1 formats like Legacy, Modern, or Pioneer, five mana for a creature that doesn't close the game immediately is too slow against linear decks and falls behind on tempo before it can generate meaningful value. Standard gives it the most charitable competitive environment among the 60-card formats simply by limiting the power ceiling of opposing decks, but it still needs a dedicated shell to be worth the investment. Vintage and Oathbreaker are theoretically legal but offer no special synergy that makes Quantum Riddler more attractive there than in Commander.
Key Combos
Combo lines featuring this card
Budget Alternatives
Cheaper options that do most of the same work
Quantum Riddler's combination of evasion and punishing mana-up opponents is specific enough that no single card replicates it cleanly, but Thieving Amalgam and Bident of Thassa both generate card advantage off combat and end-step triggers at a fraction of the price. The trade-off is that neither creates the same political pressure — opponents holding up counterspells or interaction actively feed Quantum Riddler, which is a ceiling those alternatives can't match.
Price Context
Current price
$40.28 premium tier
At $40.28, Quantum Riddler sits firmly in premium territory for a creature with a niche application concentrated in Obeka and end-step-matters builds. The price reflects low reprint probability and a dedicated fanbase rather than broad format demand, so players outside those specific commanders should weigh whether the effect is worth the cost.
Explore
Sources
Mentioned
Updated . Data from Scryfall, EDHREC, and Commander Spellbook.