Sea Stealth Attack

When this card is activated: You can activate 1 "Umi" from your hand or GY. While "Umi" is on the field, this face-up card gains these effects.
● Once per turn: You can banish 1 WATER monster you control until the End Phase; this turn, face-up Spells/Traps you control cannot be destroyed by your opponent's card effects (even if this card leaves the field).
● At the start of the Damage Step, if your WATER monster whose original Level is 5 or higher battles an opponent's monster: Destroy that opponent's monster.