Board Thread:Dragon City Mobile/@comment-5029965-20130827114608/@comment-10090661-20130913063921

You can defeat the Player with any decently trained Hybrid / Rare Hybrid Dragons that will not receive Critical hits from Pure, Sea or Flame Attacks.

I think any Terra, Flame or Metal Hybrid for the Pure Flame and any Sea or Nature Hybrid would be fine. I would suggest you review the Pure Flame and Pure Sea pages carefully to see what you will need in terms of HP for your Battle Team, then feed your Dragons as needed.

Basically, the more Stars your Battle Team Terra/Metal/Nature Hybrids have, the easier it will be for you.