Vanguard of the Restless is a rare Creature — Spirit Knight card from Secrets of Strixhaven Commander (SOC), collector number 66. Current market price: $0.27, TCGplayer market prices via Scryfall.
Flying Spirits you control get +1/+1 for each time you've cast your commander from the command zone this game. Whenever a Spirit you control enters, you may pay {2}{W}. If you do, return this card from your graveyard to the battlefield.