Agreed, but in addition to the mana consumption, I would also recommend that such a spell cost influence.

You could make the requirements be either a ton of mana, cost a shard, or cost a lot of crystal in addition to a ton of mana.  Or sacrifice a magic item of rare or greater. Or population if you're an evil tyrant and don't care.  Could also cause your sovereign to be immobilized for 10 turns.  Along with a cooldown of that many turns.  Prestige is a good idea too, making the stockpiling of it even more important. 

I missed them too, when in a game, I only found the first hero... Since then, I play with max number of heroes in world options.

I suggested in a previous post that, instead a spell of Summon Hero, give us a scroll of Summoning. The scroll could be a unique item, attached to the Hero technology tree, so u could have a total of 3 scrolls, and so 3 heroes summoned this way (levels 5, 7 and 9), I think it should be enough for a possible lack of heroes.

Another question is, how to make that scroll to cost for its use, and how much.  I guess that by a pop-up when using it, telling the costs needed could be fine. So the Sov receives a free scroll when the research finishes, but he can use it only when he can pay the price. The sov might sell the scroll too, if not interested.

And for the costs...any option is fine. Recruiting heroes only costs gildar, so using a unique scroll could cost equivalent in gildar (or maybe some more...) + some mana (for example, hero level x 10 or 20, but not much more). I don't agree with influence...but I could accept a low quantity like the hero level in influence points.

Anyway, scroll or spell, it would be fine to have it. I think that having this option would make more people (me included) to play with normal (or even low) number of heroes in world options, as a way to give a use to the spell/scroll.

The AI should be able to use the spell/scroll too...

I've been trying to avoid this in order to see when troops become any good. (haven't played 0.99 yet)

I can see myself bumping heroes up to max in the world options too.

AOW:SM had this as well but it was a random hero. They also had a raise dead hero that brought a random dead hero as an Undead hero (with undead traits on top of his/her normal traits) they also had Resurrect Hero that brought back a random dead hero.  All three of these were expensive and were only limited to the number of heros you had in the game.  So no had caps which was nice.  Currently I have onver 1000 heros in my AOW:SM data base so when you summon hero there was a the program randomly chooses from.

And heros also did a lot in the game so there was a nice pool to pull from for Raise Heros and Resurrect heros after a few turns have passed.

I'm fine with them being immortal  they can have some many injuries, they can become pretty crippled.  I hate the idea of summoning champions with magic.  That sounds very cheap.  Maybe something weaker like a henchman, but not a real champion.  

To each their own, whether they're immortal or not. 

I for one have a problem with the current system.  I've played at max champ frequency and that doesn't help me much. I wouldn't be opposed to limits or huge cooldowns or huge costs or all of the above.  I just want more champion. 

I find the same sense in a Summoning scroll than in a Summoning Spell...

If "magical" recruiting is enabled,  a way to control recruiting should be introduced... a cooldown? I find more sense in a scroll as unique item. Doing it as a unique scroll, at least you are allowed to recruit a max of 3 (for each level 5, 7 and 9), while if it is a spell, it may be cast many many times...don't like that, as heroes loses its chance of being special and sometimes hard to find. If you think that having 3 scrolls is the same, then have only 1, so it is really really unique.

seanw3 Although you have plenty of reason... an option for recruiting heroes when no one is available gives hope to continue a game. With crappy troops, sov and initial heroe only (unfortunateliy was crappy too), there is little fun in continue the game...I talk as a player, not as a hard player. I want fun, and I want having heroes to develope them...and I find reasonable to have a choice to recruit at least 1 more heroe...that way, I can play full random in game options...

Please remember that (I hope) many people that will try this game have little idea of 4x, deep strategies, empire developing, magic power combos and all things related, kind of people that if you ask: do you know MoM? they will say: of course I know my mom!