Lemuria, the Forgotten City (LED9-EN055) - Legendary Duelists: Duels From the Deep 1st Edition

This card's name is treated as "Umi". All WATER monsters gain 200 ATK and DEF. Once per turn, during your Main Phase: You can have all WATER monsters you currently control gain Levels equal to the number of WATER monsters you currently control, until the End Phase.