Is Swift Warden legal in Standard, Modern, and Commander?

Swift Warden is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Swift Warden

Q: What type of card is Swift Warden?

Swift Warden is a Creature — Merfolk Warrior. Its oracle text reads: "Flash When this creature enters, target Merfolk you control gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.) *A warning shout would take too long.* Power/Toughness: 3/3"

Creature — Merfolk Warrior

Flash

When this creature enters, target Merfolk you control gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

*A warning shout would take too long.*

Power/Toughness: 3/3

Set Rivals of Ixalan

Rarity Uncommon

Mana Value 3

Artist Viktor Titov

Collector # 146

Scryfall