Elemental is tagged as strategy game in an RPG world.
Much has been said about heroes needing some *oomph*.
Personally, I would go a step further and heroes should be "segregated" into classed.
Currently heroes offer various boni, but overall they're not very useful, unless they have a lot of mana. Which you can then use to summon creatures (the specifics of this is subject to the magic system which, frankly, needs some serious rebalancing). If they're not a caster then you can spend oodles of cash to upgrade their equipment, and let them tag along to battle to have them level up, but chances are that they'll be turned into a bloody pulp by the first troll they meet. Another use is of course having them pick up the lost crates, lost purses, and all the other non-combat goodies that pop up when you research the Adventure tree.
It has been much discussed how to make them more useful, and if my suggestion has been made already I apologize, but these forums move fast.
I would love to see heores put in classes:
1. The Administrator. They help with gildar revenue, research point production, food production etc. in the city they're in. They level up by doing their job - pencil pushing. E.g. after 20 turns they're LVL2, after another 30 turns they're LVL3 (or whatever speed seems the most balanced).
2. The General. They're not great warriors, but they know how to lead armies. They give boni to attack, defense, movement etc. They gain experience through battles. The higher their level, the bigger the bonus and the more units could benefit from their skills (e.g. at the start only units with a size of 1 get the benefit of his leadership, later units of size 4 etc.). Make him work his way up the ranks.
3. The scoundrel. Thieves, spies, assassins, saboteurs. They infiltrate the enemy, stealing his stuff, disrupting production, maybe even assassinate enemies. They may be able to use a bit of magic, but there should be ways to counter them. A scoundrel's life shouldn't be easy. Successful missions give XP.
4. The Champion. Warriors, mages, who in their highest levels and with best equipment can take on dozens of enemies alone. Basically the current heroes, but with some buffing.
5. (Maybe) Mixed classes. Someone might be a General and Administrator. Or a Champion and a Scoundrel. But they should never be as effective in both as if they were "single class".
I'd also implement a limit of 3 heroes per army stack to avoid "superstacking" of boni.
"But Syt," you ask, "what about dynasty characters?"
Well, I would love something like the system from Crusader Kings implemented where you pick an education for your child that molds his or her future (I think adding childhood events would take this too far), and when they grow up you get to select the class they're in.