Sorcerer Kingdom's Covert Invasion

Sorcerer Kingdom's Covert Invasion was the invasion of the Re-Estize Kingdom by the Sorcerer Kingdom during the conflict between the two nations. As the name implies, it was done covertly, with the Kingdom having no idea that war had broken out.

Battles
The exact events of these battles are unknown. However, it mostly ended with the same result: the Sorcerer Kingdom's forces massacred all inhabitants of the territory they invaded.

The battles were so one-sidedly in their favor that the Sorcerer Kingdom even used it as an opportunity to experiment with new battle tactics. For example: in one battle, an army of Elder Liches was used to bombard a city in submission. Another was to airdrop undead using their recently acquired Frost Dragons. Mare, meanwhile, would simply use his nature magic to flatten entire cities and killing their population in one go.

Demiurge was in charge of information suppression to prevent the Kingdom's government from becoming aware of the situation. By using his Shadow Demons, the Floor Guardian was able to create a vast network that sought to it that no soul who entered conquered territories left alive.

Not all conquests ended in massacres, though, as Albedo was able to use the sheer infamy of the Sorcerer Kingdom to pursue several nobles into surrendering. One of these was Marquis Raeven, who would go on to point out other non-corrupt nobles to spare. These nobles would also aid with the information suppression by harboring refugees from fallen territories and preventing anyone from leaving their domain.

Aftermath
After successfully massacring and conquering a considerable amount of the Re-Estize Kingdom's territory in secret and successfully cutting off any form of transportation or communication with their remaining allied nation of the Argland Council State due to now taking control of the East and Northern halves of the Kingdom. The Kingdom's villages,cities and town were thus then massacred and slaughtered in mass to insure complete secrecy to the Sorcerer Kingdom's actual movements and successfully keeping the Kingdom's Western region that contained the Royal Capital oblivious to their invasion. However despite the gigantic success and gains obtained by the Sorcerer Kingdom and the new experience and knowledge the Floor Guardians obtained in warfare from their trial and error experience destroying cities,villages and towns, a few of Nazarick's denizens, who were sympathetic to the slaughtered humans, were secretly outraged by the barbaric actions done by their comrades and immediately made their discontent known during their plea for mercy for the innocent humans with their master regarding the invasion.