Water Bomb

You hurl a dart of aqua. Choose one creature you can see within range. The target must succeed on a Dexterity saving throw or take 1d6 Cold damage and soak the enemy meaning until your next turn (when the water washes off) the target has disadvantage on it's next saving throw against a spell that would deal Lightning damage on a fail and all attacks have advantage if they also deal lightning damage to the target.

This spell’s damage increases by 1d6 when you reach 5th level (2d6), 11th level (3d6), and 17th level (4d6).