Master of Waves is a mythic Creature — Merfolk Wizard card from Theros (THS), collector number 53. Current market price: $1.24 (foil $4.37), TCGplayer market prices via Scryfall.
Protection from red Elemental creatures you control get +1/+1. When this creature enters, create a number of 1/0 blue Elemental creature tokens equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)