It would be nice to see better stats for Legendary dragons in general. With many Legendary dragons, max HP is lower than Epic for the same level and grade. It doesn't make any sense.
Also, it would be nice to have some way to compete in the Leagues with users that have Heroic dragons. Heroic dragons are overpowered, yet they are somehow easier to obtain than has been my experience. Heroic dragons flood the Leagues at level 40+, making it near impossible to advance any further without one.
I've reached a peak in the game where I can't advance without a Heroic dragon. Is this intentional? It seems unfair. If you're going to make it that difficult to obtain one, users should still be able to advance without it.
Just my opinion on improving the battle system. Thanks.