Apologize if it was already posted or very similar to other ideas.
This is yet another proposal and another version of Hero Academy, which i think could be reasonable for both parts (Developers and players).
The concept is pretty much this:
At the final level of the Hero Academy you unlock the heroes generator window.
The heroes generator window allow you to develope a specific hero using your duples in specific ways.
You have 4 settings: Rarity - Class - Color - Origin.
Every setting can be upgraded for a max of 100% and using at max 10 cards.
Rarity of the cards improve chance for that setting.
Just using same kind of heroes for the example, but they can be mixed.
Example: I want to make a Delilah.
I will need:
Rarity : 1 legendary (any)
Class: 2 Elenas or 10 Boldtusks (legendary increase 50% chance, 10% epic, 2% rare). All of them are fighters.
Color: 2 Leonidas or 10 Wu Kong (again 50% chance legendary, 10% epics, 2% rare). All of them are yellow.
Origin: 1 Hotm
So at best you can use 6 specific heroes to get another specific hero, or eventually 22 specific less rare heroes.
Another example: generate a Guardian Falcon.
Rarity: 1 epic card
Class: 2 Justice or 10 Sonya
Color: 2 Khagan or 10 Kelile
Origin: 1 Lady Locke or 5 Merlins (100% legendary, 20% epic, 4% rare)
Third example: Master Lepus.
Rarity: 1 legendary (any)
Class: 2 Kadilen or 10 Melendor
Color: 2 Magni or 10 Grimm
Origin: 1 Santa or 5 Valeria
And so on…
Open to any criticism, just need to put this idea to paper (or screen) 