Is Veiled Sentry legal in Standard, Modern, and Commander?

Veiled Sentry is legal in: Legacy, Vintage, Commander.

Veiled Sentry

Q: What type of card is Veiled Sentry?

Veiled Sentry is an Enchantment. Its oracle text reads: "When an opponent casts a spell, if this permanent is an enchantment, it becomes an Illusion creature with power and toughness each equal to that spell's mana value."

Enchantment

When an opponent casts a spell, if this permanent is an enchantment, it becomes an Illusion creature with power and toughness each equal to that spell's mana value.

Set Urza's Saga

Rarity Uncommon

Mana Value 1

Artist Ron Spears

Collector # 109

Scryfall