Azorius Guildmage is a uncommon Creature — Vedalken Wizard card from Ravnica Remastered (RVR), collector number 165. Current market price: $0.21 (foil $0.37), TCGplayer market prices via Scryfall.
{2}{W}: Tap target creature. {2}{U}: Counter target activated ability. (Mana abilities can't be targeted.)