Is Scourge of Valkas legal in Standard, Modern, and Commander?

Scourge of Valkas is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Scourge of Valkas

Q: What type of card is Scourge of Valkas?

Scourge of Valkas is a Creature — Dragon. Its oracle text reads: "FlyingWhenever Scourge of Valkas or another Dragon you control enters, it deals X damage to any target, where X is the number of Dragons you control.{R}: Scourge of Valkas gets +1/+0 until end of turn."

Creature — Dragon

Flying<br>Whenever Scourge of Valkas or another Dragon you control enters, it deals X damage to any target, where X is the number of Dragons you control.<br>: Scourge of Valkas gets +1/+0 until end of turn.

Set Pioneer Masters

Rarity Rare

Artist Lucas Graciano