Ruthless Waterbender is a uncommon Creature — Human Soldier Ally card from Avatar: The Last Airbender Eternal (TLE), collector number 110. Current market price: $0.18 (foil $1.14), TCGplayer market prices via Scryfall.
Waterbend {2}: This creature gets +1/+1 until end of turn. Activate only during your turn. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)