Is Arni Brokenbrow legal in Standard, Modern, and Commander?

Arni Brokenbrow is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Arni Brokenbrow

Q: What type of card is Arni Brokenbrow?

Arni Brokenbrow is a Legendary Creature — Human Berserker. Its oracle text reads: "Haste Boast — {1}: You may change Arni's base power to 1 plus the greatest power among other creatures you control until end of turn. (Activate only if this creature attacked this turn and only once each turn.) *"I headbutted a troll. And won."* Power/Toughness: 3/3"

Legendary Creature — Human Berserker

Haste

Boast — : You may change Arni's base power to 1 plus the greatest power among other creatures you control until end of turn. (Activate only if this creature attacked this turn and only once each turn.)