Water queens regenerate half their hitpoints OUT of water. Fully equipped, plus quickness, they can have over 31 defence. No elemental royalty can regenerate faster than a waterqueen, and only the fire kings, who can't regenerate, has a chance at hitting the waterqueen. The water queen can basically win against any royalty in or out of the water.
Even though she had 50% fire resistance, the fatigue skyrocketed when the fire elementals were attacking. However, for some strange reason, the fatigue could not go above 190. Why is that? Is it because elementals can't die of fatigue?