I slayed the dragon yippie. I just kept skipping it when my 2 starter heros got to level 15. I blocked the door to the red dragon and my heros ended up 18 18 15 16 13 15 5. Yay. If your having trouble and your heros keep dying keepyour heros on the weaker levels and just keep on skipping it until they are high of a high enough level to your like.