Water Pledge is a damaging Water-type move.
If a teammate uses Fire Pledge in the same turn, a rainbow will appear on the target's side of the field for four turns that doubles the chance of Pokémon's secondary effects occurring.
If a teammate uses Grass Pledge in the same turn, Grass Pledge's effect will be triggered.
In both cases, Water Pledge's power is doubled if it is used after the other pledge move.
By Egg Move