Sorcerer Kingdom's Covert Invasion

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 all 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 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.