Retcon the lore. Instead of swords and magic against swords and magic. It's guns, swords and tanks against guns, swords, and magic.

Ten years of mankind living in peace after the unification war, until the Elves launch a surprise invasion. However the elves came unprepared, they thought they were invading a species of backward primitives ready to be enslaved, only to face humanity's might and wrath. The invasion force was destroyed within hours with few survivors only to be captured and interrogated. Eventually, the humans soon discovered a realm gateway where the elves came from.

As the Human Alliance was deciding the next course of action, they encountered and contacted by beastfolk rebels that came through the realm gate in hopes of trying to help them to fight off the elves, but were amazed they defeated them. The rebels told the Alliance of their situation with the Elven Empire, how much they know about them, the realms, what they're doing to their people, and won't be long until the Empire figures out what happen to the invasion force. With being told of the information, the answer was clear: Mankind has only one option. Attack.

With no time to lose, the Alliance led by the Liberator Triumvirate (Aurelian, Solis, and Augustus Gustave) and their new beastfolk rebel allies prepared for their invasion into the occupied realms. The first realm they attacked caught the elves by surprise, and there was no hope on slowing the humans advance. In a matter of hours, the humans liberated the realm while suffering minimal casualties. From that moment they continue liberate more realms with ease, until the elves finally managed slow their advance to a stalemate when the Alliance freed 65% of the realms from the Empire. The stalemate only lasted for 4 years, until the Empire was losing control of law and order within their territories.

Unfortunately for the Elves, slave uprisings and new rebel factions have been forming when they heard that their salvation and freedom was approaching. The elves tried to put uprisings down but as soon they take care of one, another or three more uprisings started. Left with little options, High Queen Arvae ordered all of the Elven Imperial forces to withdraw and gather and defend "The Heart of Elven Civilization", as she puts it (which are twelve realms), but leaving the slaves and rebels be. With that, all of the once Elven Empire occupied realms and all its inhabitants, are free. But the Humans war with the Elves is not over.

After consolidating territory, and restoring law and order, the siege of the Elven Empire core realms commenced. The campaign lasted for 5 years as the elves fought where they stood until at the end of the Siege of the Elven Capital Realm, the Alliance glassing a realm making uninhabitable, and forcing Arvae to surrender.

The Great Human-Elven War went on for almost roughly above nine years until the end of the Siege of the Elven Capital Realm. Arvae and her loyalists were banished to an isolated realm where they were never heard from again.

Millennia later after the Holy Civil War and the formation of the United Imperium, Arvae and her subjects returned for revenge for their humiliation of the Great War. To this day the war between mankind and elvenkind still rages on. Some call it the Second Great Human-Elven War, but many others, it is the Eternal Human-Elven War. For the Great War never really ended, and the only way it can end is the total annihilation of one side.