Is Twisted Riddlekeeper legal in Standard, Modern, and Commander?

Twisted Riddlekeeper is legal in: Modern, Legacy, Vintage, Commander, Historic.

Twisted Riddlekeeper

Q: What type of card is Twisted Riddlekeeper?

Twisted Riddlekeeper is a Creature — Eldrazi Sphinx. Its oracle text reads: "Emerge {5}{C}{U} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.) When you cast this spell, tap up to two target permanents. Put a stun counter on each of them. (If a permanent with a stun counter would become untapped, remove one from it instead.) Flying"

Creature — Eldrazi Sphinx

Emerge (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)

When you cast this spell, tap up to two target permanents. Put a stun counter on each of them. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Flying

Set Modern Horizons 3

Rarity Uncommon

Mana Value 8

Artist Nino Vecia

Collector # 14

Scryfall Gatherer