The Chance of Victory is estimated on the rarity of the Dragons. If you have a Unique or Rare Dragon on a lower level the chances will be better than having a Common Dragon on high level. It is advisable to have a variety of Health, Attack and Range Dragons. The difficulty will scale with the level you have. In order to win the Battle, you ultimately have to destroy Alvin's ship . A good strategy is needed and Dragons with different skills should be matched to the target. For example, use a Target Dragon to attack an Armored Ship, which can only attack on short distance.