It would be great to have a mechanism to be able to “retire” heroes by recycling them in the Hero Academy for emblems or rare mats. I know soon we’ll be able to covert 5* into a random other 5* but in the case where we have a lot of unused, unleveled 4* and 5* heroes it would be great to simply convert them into resources. So then we have 2 options for use of unused heroes.
Side note: Hero Academy also really needs to option for rerolling 4* heroes, not just 5* heroes as we see in beta. If not, at least the suggestion above gives us then a use for unused 4* heroes.