Going back through the posts today I saw some very good points that I agree with...
1) It doesn't matter what abilities you choose for your sovereign are.. after you gain a few levels you can get all of the ones you missed. The *abilities* you pay for in the beginning ought to also contain selections that you CAN NOT get anywhere else. Sure--choosing spell trees wouldn't apply here, but maybe the sovereign has, I don't know, some inherant magical nature where every military unit he/she produces has a 10% chance of gaining magic immunity, or a sovereign who was born on the elemental plane enabling them to command multiple elementals of the same tpye (perhaps a group of three fire elementals), and so-on. Or make it simple... they get a 20% bonus to construction. But make them buffs that you cannot gain just by leveling. Wait--spell trees COULD apply here. Let's say the maximum spell level for ALL heroes is level 3, but you can choose "expert" or "wizard" for any of the 5 trees, allowing you to gain access to spells of that level.
2) GOT to have a larger selection of races, and allow some to train fantastic creatures. Think HOMM on this one. Let there be a death race that can train skeletons and wraiths, etc., etc.
3) Magic. Please, oh PLEASE let's make "War of Magic" actually mean something. I made a few posts about this... I still think that we need a slider for mana... let it be for technology research, spell research and mana generation. You can STILL have materials for weaponry, construction, etc. Set it up so that researching spells takes a LONG time. On the game map, have locations/quests where you can discover a scroll for a certain spell. The more advanced the spell, the tougher the monsters. You will WANT to take those risks because the spells are hard to research. Once you have the spell, they are availabe to ALL of your champions but... the champions have to learn them. IF stationed in a city, they learn them 4x as quick as if they're exploring, etc. Maybe this will be one of the buffs... perhaps a "Fire Scholar" buff enables that hero to learn fire-based spells 10x faster, etc. Also, if you want to learn fireball, your hero must first have mastered sparks and flame dart, etc.
As for the spells, they need to level, too. Presently--the more fire shards you have the more damage a fire spell does. BUT... they overall nodes you control should have some effect. As I mentioned in another post, let's use fireball for instance. You cast fireball and have no shards. It hits only one enemy for the base damage. If you control 3 fire shards and 6 other shards, the damage is increased due to the fire shards, but the area of effect is larger due to the other shards you have (maybe one square in front and behind the caster for 3 other shards, a 9x9 area for 6 other shards, and so-on). Also, maybe have a knock-down/knock-back effect for some spells as a buff. Flame dart... if you control 3 shards other than fire, there sia 50% chance the target will be knocked down for a turn, or knocked back 1 square, etc.
I love the quote you see every now-and-then on the loading screen. "Need an army? Summon one". You're kidding--right? The summoning is pretty bad. Let the caster put SEVERAL units on the field like in MoM. From weak ones (wolves, goblins, etc) all the way to perhaps a dragon. Let the mana cost scale accordingly, and also let the caster choose an amount of mana to "buff " a spell with like in MoM. On summoning, choosing more mana allows the goblins to be a higher level with more HP, damage and defense. That becomes strategic. Do I summon 3 weaker units of goblins, or one unit of uber goblins? Same with dragons... a level one dragon (youngling) is petty doggone tough, but buff it with mana to get all the way to an ancient dragon that can do a massive AOE fire attack. Let some summonings be for combat ONLY.
Doing this with spells, and especially letting you buff them for greater effect/larger AOE will make the battles extremely more strategic. You can have fun with it, too. Let there be recommended minimum intelligence for a certain spell. Like fireball... the recommended intelligence may be 35. If you're below that, there's a chance it will fizzle, backfire, hit a party member, or just cause a big cloud of smoke on the battlefield. If your intelligence is way higher, say double the amount, let there be a 3% chance of some random effect like charring the enemy where they are immobilized for a few turns, or 20% of the enemy armies are turned into guinea pigs, etc.
I also feel weapons and armor for heroes should be buffed by the shards you control. Not just to add damage, but also effects. Like the "Bow of Wind". If you control 3 air shards there's a 50% chance an enemy will be knocked down/back and so-on. That will make things good for those who like melee heroes, but it's still magic-based (here again, War of MAGIC).
Make the tree you choose more selective. Make big-time spells need an 80 intelligence, so you need to focus all of your levels on gaining intelligence. Same with melee--the Sword of Meteors can only be wielded by a champion with a strength of 80.
Lastly, we NEED spells for immobilization. Like old school D&D. Paralysis, sleep, freeze, etc. Again--effects are based on shards, type, etc., as well as monster level and resistance. And, of course, any frozen, immobilized, etc., enemy is muce more prone to a critical hit.
I would LOVE to see this game get to the point where you'd sell your own Mom to get that *one more* fire shard so you can enable some effect on a weapon, gain a new effect on a spell, summon a certain creature, etc.