There has been a lot of recent discussion about people not getting the value from what they are purchasing, which has led them to argue for hero trading. While I believe hero trading would be a bad idea and ruin the game, I do think something should happen about hero glut.
What I propose is to have a re-rolll system. For example, you can take five 5* heroes and use them to turn them into a random 5* hero (or random hero of equivalent * level). The reason why I say this that some of us have tons of duplicate heroes. For example, byeond the first one, so the rest are duplicate, I have extras of the following: 3 drake lee, 2 gregs, 2 vivicas, 2 Zim-kitty, 2 leo, and 2 marjana. While there are some heroes that you want two, most 5s and even 4s are not worth having more than or two of. I can’t ever see myself fully ascending 3 vivica or 3 gregorians; However, it would feel really bad to just feed them for a paltry amount of exp to another hero, especially when they are so expensive to acquire. Other games that have been around for a long time have a similar feature: they let you combine heroes into stronger ones, they let you re-roll on heroes given you have specific materials, and so on.
It could even be set up where there is a 1% chance to get a hotm, 2% for event heroes, 10 % for atlantis heroes, and then the rest would just be regular TC heroes…or something to that equivalent.