Is Lionheart Maverick legal in Standard, Modern, and Commander?

Lionheart Maverick is legal in: Modern, Legacy, Vintage, Commander, Pauper.

Lionheart Maverick

Q: What type of card is Lionheart Maverick?

Lionheart Maverick is a Creature — Human Knight. Its oracle text reads: "Vigilance {4}{W}: This creature gets +1/+2 until end of turn. *"Your signet is no symbol of power. It marks only your need for numbers to aid you. What do you do, guild-rat, now that you face my blade alone?"* Power/Toughness: 1/1"