Whenever you want a heroic dragon, you always have to win a heroic race or get to lap 12 or 15, however here are my ideas on other ways to get heroic dragons,
*collecting 1000 heroic orbs
They should be rare for extra hard work
- fighting many times against tough dragons
They might be max but for nerf,they are not gonna have any stars.
Just like the missions for getting your guardian tower, you have to do missions to get the heroic dragon, the missions will probably be hard.
I suggested these ideas because I'm getting bored of races(they are still good though).