Is Conundrum Sphinx legal in Standard, Modern, and Commander?

Conundrum Sphinx is legal in: Modern, Legacy, Vintage, Commander.

Conundrum Sphinx

Q: What type of card is Conundrum Sphinx?

Conundrum Sphinx is a Creature — Sphinx. Its oracle text reads: "Flying Whenever this creature attacks, each player chooses a card name. Then each player reveals the top card of their library. If the card a player revealed has the name they chose, that player puts it into their hand. If it doesn't, that player puts it on the bottom of their library."

Creature — Sphinx

Flying

Whenever this creature attacks, each player chooses a card name. Then each player reveals the top card of their library. If the card a player revealed has the name they chose, that player puts it into their hand. If it doesn't, that player puts it on the bottom of their library.

Set Commander 2018

Rarity Rare

Mana Value 4

Artist Michael Komarck

Collector # 84

Scryfall Gatherer