Bolivar (Elves, Talannar) won against Elemental God (Demons, Grol) on the sun map, at the end of the 2nd month, I don't remember the exact date.

Turns 1, 7.
Talannar had a full set of Dwarf artifacts, light, chaos, firearms, and over 1000 mana. I couldn't see Grol's artifacts clearly, but it seems he had a Necropolis staff, and he somehow gathered over 1000 goblins with magic resistance, probably from some kind of guard unit, like 5,000 goblins, and then upgraded them. However, the goblins couldn't disrupt the spells.
The Elves also had another hero, Iranna, level 23, with skilled machines, chaos, and sharp mind. She wasn't useful in the final battle; she was conquering territory from the opponent and was already approaching the enemy castle.
The final battle took place in the Elf castle. Talannar was level 30, and Grol was level 31. Meteor Shower with over 900 damage and 4 cursed spells left the opponent with no chance (considering the summoned demons, it was simply overwhelming; a dungeon doesn't deal that much damage in one turn). Talannar's troops, with dispersion and obedience, dealt weak damage, and essentially the entire battle was won by the hero.
The battle recording is available at http://rghost.net/78L4m2GvJ
Thank you for the game.