Is Opal Guardian legal in Standard, Modern, and Commander?

Opal Guardian is legal in: Modern, Legacy, Vintage, Commander.

Opal Guardian

Q: What type of card is Opal Guardian?

Opal Guardian is an Enchantment. Its oracle text reads: "When an opponent casts a creature spell, if this permanent is an enchantment, this enchantment becomes a 3/4 Gargoyle creature with flying and protection from red."

Enchantment

When an opponent casts a creature spell, if this permanent is an enchantment, this enchantment becomes a 3/4 Gargoyle creature with flying and protection from red.

Set Time Spiral

Rarity Rare

Mana Value 3

Artist Christopher Rush

Collector # 30

Scryfall Gatherer