Can we not have an "all your eggs in one basket" system so you can stop the whole "get exactly 100 grains of sand" or "till the amount upon which you upgrade your building". Basically quality of life changes, please, if possible.
Uses what's left of the human population to win>Extinction of humans>Devils and demons still win,no?
Uses heroes>they die and revive>send them on quests>Win>rinse and repeat>what's left of the human population sits back and watches.