Fire Nation Turret is a rare Artifact card from Avatar: The Last Airbender Eternal (TLE), collector number 64. Current market price: $8.14 (foil $7.17), TCGplayer market prices via Scryfall.
At the beginning of combat on your turn, up to one target creature gets +2/+0 and gains firebending 2 until end of turn. {R}: Put a charge counter on this artifact. Remove fifty charge counters from this artifact: It deals 50 damage to any target.