It is a good meat-shield (water-shield?) that helps keep the heat off me for a few turns, but the problem is that it's slow to optimize its strategy against enemies. This is the basic strategy it uses most times (in my case):
Turn 1: Uses Sprite. Turn 2: Uses Elemental Shield Turn 3: Uses Taunt. Turn 4: Uses either Storm Trap, or Sprite on me. Turn 5: Uses Spirit Armor or Elemental Shield. And repeats, but omits Turn 2 if used ES for Turn 5.
How about it omits Turn 1 until it gets hit? This would allow for my wizard to not get hit too much before I start crossing my fingers the entire match that it throws a Sprite at me. And it's quite rare if it uses Spirit Armor against any Spirit enemies; it should throw one up instead of ES against any Spirit enemies.