Heres the map I made in like 5 minutes. I took the Random World Generator and generated a map that can have 32 civs on it.
*Certain Civs are in the correct place (Amazons in the jungle, not tundra, Norse in the Tundraish area not desert), and other civs can be most anywhere there is a starting location.
*altered it so you need high magic and warpstone to build the firestorm spell
*made locked alliances, with the chaotic factions vs the Old world factions, and a undead neutral faction
*altered the victory conditions so you need 80% to dominate the world
*made the pillar of skulls give a skeletal minion every turn in the city that built it.
*removed the maintenence cost for Undead state