Magus of the Arena is a rare Creature — Human Wizard card from Planar Chaos (PLC), collector number 104. Current market price: $0.17 (foil $0.50), TCGplayer market prices via Scryfall.
{3}, {T}: Tap target creature you control and target creature of an opponent's choice they control. Those creatures fight each other. (Each deals damage equal to its power to the other.)