How about opening new strongholds in Atlantis and eventually Valhalla once people have “conquered the lands.” It would only need to be a basic outpost with maybe some houses For recruits, a mine and a farm and most importantly A NEW TRAINING CAMP! This would allow players to be have a chance at training hero’s from the specific season and would allow for greater diversification of hero rosters. You could actually incorporate it into Valhalla in the yet-to-be-released levels by having new loot available for completing levels (similar to town loot for using titan harpoons) so that this specific loot is what is required for training hero’s… just spitballing here guys but I think most players would agree
I support the idea of training camp from valhalla or atlantis as a prize for beating stage. Beating it on easy mode awards you chance of 3 and 4 * heroes, beating on hard mode awards you chance of 5* heroes
Similar idea without the training camp
If they ever create a decent Hero Academy, you could also retrain Season 2, or Season 3, heroes into different heroes from the same Season.