Azesion-Dilhade War

Azesion-Dilhade War is a war that occurred between the human continent of Azesion and the demon kingdom of Dilhade. The conflict was orchestrated by Commander Jerga in an attempt to exterminate demonkind, but it was stopped by Anos Voldigoad and his allies before it could escalate into an all-out war.

Prelude
After the Great War ended with the Demon King Anos' sacrifice, magical barriers were erected to isolate the four races so that their hatred would disappear in due time. Knowing that the Demon King would return, Jerga founded the Hero Academy to pass on his hatred to future generations. He falsified the events that occurred, such as the Hero Kanon slaying the Demon King and raising the walls to protect the allied races from demon retribution. However, history books alone wouldn't be able to pass on the hatred they felt, so Jerga split his source into two magics: Jerga and Eleonore. As magic, Jerga instilled his hatred into the hearts of those who used Aske, while Eleonore was used to raise an army of cloned heroes.

Many supported Jerga due to the atrocities the Demon King committed during the war, but Hero Kanon opposed this since he was aware of the Demon King's true benevolence, so Jerga's supporters killed him as a result. However, the hero was able to fake his death and move to Dilhade, whose citizens were more understanding.

His plan was to create a phony Demon King, Avos Dilhevia, to take the full brunt of humanity's hatred. He used Evansmana to sever Anos' fate as the reincarnated Demon King of Tyranny, completely erasing his name from history. Those who could not forget moved away from Dilhade and remained quiet until it was over, while the Hero Academy simply believed he had changed names. As part of his plan, six of the Seven Demon Elders willingly ceded control of their bodies to Kanon's other sources. With his remaining source, Kanon would reincarnate throughout the years as he made counter-plans of his own.

Declaration of War
Two thousand years later, when the Demon King was expected to return, the Demon King Academy and the Hero Academy held an educational exchange. While Dilhade saw this as a learning opportunity, Azesion used this opportunity to humiliate the visiting demon students and create justification for war. At the same time, Lay Grandsley, Kanon's latest reincarnation, sent the remaining three Demon Elders under his control to Gairadite. Together, they attacked the hidden temple where Evansmana was enshrined and reclaimed the holy sword, giving Diego his highly coveted justification.

After the theft of Evansmana, the Demon King Academy students were confined to their dormitories, while Diego sent a magic broadcast across Azesion announcing the return of the Demon King of Tyranny Avos Dilhevia, who had stolen the legendary holy sword alongside three of the Seven Demon Elders. Diego lamented that the demons would do something this despicable, even after he tried extending a hand of friendship by holding the educational exchange, but they took advantage of his kindness and stole Evansmana to invade human lands. He then reassured the citizens that there was nothing to fear, as the King of Gairadite had reformed the Demon King Subjugation Battalion, which once defeated the demon king.

Meanwhile in Dilhade, Medoin Garsa, Zoro Angart and Eldora Zaia issued a magic broadcast declaring that they had discovered the reincarnated Demon King of Tyranny. Avos Dilhevia then revealed himself to the citizens of Dilhade and proclaimed his return, stating that he had sacrificed his life to divide the world and spared the humans out of mercy, but they held on to the Sword of Three Races to destroy him and even trained an army with new techniques to kill demons. He was wrong in saving such foul and abhorrent fools. However, Avos reveals the stolen Evansmana and proclaims that he has obtained humanity's greatest weapon, so his descendants didn't have anything to fear. He then announced his intention to destroy humanity with the aid of his followers.

Anos meets with his followers to discuss the fallout of recent events as they discussed how to stop the incoming conflict. While Anos initially wanted to fight alone, his friends and followers convinced him to let them fight as well. Before the grand battle, Lay reassured Misa and asked for half of her one-shell necklace due to a popular legend stating that it could reunite lovers in the afterlife.

The Battle
Both human and demon armies set up encampments on their own side of the border in the Tola Forest, as it was only a matter of time before they clashed. However, Anos had sent his companions to intercept the armies and delay them before they clashed, as Misha and Sasha were sent to fight the a band of demons that were trying to link up with the main demon army, while Lay and Misa took care of the advanced forward units of royalists that were advancing, with the Fan Union providing battlefield reports.

Meanwhile, Anos and the Demon Elders aligned with him went to flush out Avos and his Demon Elders at the Dilhade army's base camp. The soldiers initially thought that Anos' Demon Elders were there to support them, but Anos quickly launched a surprise attack to overwhelm them. When Avos' Demon Elders moved to engage their peers, Anos took the chance to slip away and confront Avos, but he only found the Sword of Three Races at the castle. Anos then received a Leaks communication from Misa stating that she lost contact with Lay, with Anos noting that his Gyze link with him was severed as well. Anos also receives a message from Melheis reporting the defeat and capture of the remaining Demon Elders, but the sources controlling them had abandoned them.

After realizing the truth about Avos Dilhevia, Anos teleports to the Azesion side of the border and finds the fake Demon King there. After a brief clash, Anos calls him by his real name— Hero Kanon, or more accurately, Lay. Avos then removes his mask and confirms Anos' suspicions, asking how he was able to figure it out. Anos points to various clues, such as Lay's knowledge of the one-shell necklace, his ability to wield holy swords, his lack of recall after mastering the Sword of Intent, and the sources fused with the Demon Elders. When asked about his motivations for becoming Avos, Lay brings up Jerga's plot to destroy Anos and restart the war. He accelerated Jerga's plan because he intended to die in place of Anos. He felt like Anos had already sacrificed enough, and it wouldn't be fair to take him away from the peaceful future he made. That's why he took command of the demon army as "Avos Dilhevia".

The two friends then fought fiercely to incapacitate one another, as Lay wanted to sacrifice himself while Anos was unwilling to let his friend die to end the war that should have ended ages ago. Anos managed to destroy six of Lay's seven sources, but Lay was unwilling to give up and began wielding his holy and demon sword simultaneously. Realizing this, Anos led Lay to a public location and tricked him into piercing his source with Evansmana. He also swapped their outfits so that he appeared to be Avos Dilhevia and Lay as Hero Kanon's reincarnation. Anos, now pretending to be Avos, told his demon followers not to seek revenge against the humans and to await his reincarnation. While enraged at their master's death, the demon army retreated as per their master's final command.

However, they were attacked by a rabid Diego who wanted to continue the conflict until all of the demons were killed and declared that Lay was an imposter posing as Kanon. The demons were protected by Eleonore who used a barrier to stop the spell. Diego then ordered the Zeshia clones to self-destruct, but they resisted his commands. Angered, Diego attempted to detonate their Gavuel manually, but Lay was able to slice off his hand to stop it. Diego orders his subordinates to attack Lay, but they aren't willing to due to acknowledging Lay as the returned Hero Kanon. Lay dared Diego to try to wield Evansmana as the holy sword rejected him and his troops began to depart back to Azesion.

Jerga's Return
Diego then activated Aske, which resurrected Jerga as a demon-destroying spell. Jerga was disappointed in Kanon/Lay for defending the Demon King and even reincarnating as a demon himself, but Kanon/Lay returned the sentiment, expressing sadness over seeing his mentor reduced to a spell that embodies hatred. He tried to defeat Jerga quickly, but due to the fact that the Jerga spell was holy magic, Evansmana wasn't capable of destroying another holy being. Jerga then proceeded to reactivate the Gavuel magic circles on the Zeshia clones. Misha and Sasha fused together into a singular being to fight Jerga and stop the Zeshia clones from exploding. Lay and the others attempted also joined in, but there were too many clones spread out to stop. Just as it seemed that the Zeshias would explode, the activation of Gavuel was stopped by Rivide from a resurrected Anos.

Jerga then attacks Anos with a sword made of Aske, as Anos parries the blow and crushes his Aske-formed body with Vebzud but Jerga reforms immediately. Jerga then drains the hope of the humans of Azesion into himself in order to power up and uses it create a armor for his spectral form and a holy sword. He then continues to attack as Anos orders his followers to take the wounded to safety, as Aisha creates a Demon King Castle which is reinforced by Melheis. Misa then uses Fuska to conceal the castle and its entrance as Jerga is shocked to believe that the spirits have sides with the demons, although he later believed that Anos enslaved them to aid him. Lay comes back to assist Anos after regenerating all of his extra sources. The two teamed-up to fight Jerga together.

Anos is eventually able to summon his castle Delsgade via a origin spell, as he was able to use Venuzdonoa to destroy the reasoning that prevented Evansmana from harming holy beings like Jerga, as Lay cut off and destroyed his arm. Anos had the Fan Union sing to use Aske to replenish his magic power as he and Lay performed one synchronized attack to destroy Jerga and remove him from the world's order, as Anos granted him one last mercy and reincarnated him so he could meet with his family, who were killed by Anos but also reincarnated by him.

Aftermath
Upon returning to Dilhade, the entire infantry of the Demon King Army knelt before their true Demon King and pleaded for his forgiveness for their negligence towards him, Anos forgave his troops and settled with them serving him for the rest of their lives.

Diego is sentenced as a war criminal for cutting off his adjutant's arm when he disagreed with Diego. Despite achieving their goal of killing the Demon King of Tyranny and making the Demon Army retreat, Diego called for the continuation of war until their enemies were annihilated. Due to the appearance of the real Hero Kanon, who, with the Sword of Three Races in hand, protected the people of Azesion from the Demon King of Tyranny, the other reincarnations were deemed fakes. The Hero Academy remains active, but it will no longer have receive vast budget it once did. After the battle confirmed Hero Kanon's return, Azesion requested information from Dilhade in regard to Hero Kanon, as they were unaware of his true identity despite some members of the battalion seeing his face, as his true identity as a demon wasn't public knowledge and was only known to the higher-ups of Azesion.

Ninety percent of the people who had their hope forcibly drained by Jerga make a full recovery, while the remaining ten percent are in stable condition. His actions are erroneously believed to be the Demon King of Tyranny's, making him a symbol of fear in this age as well. To counter this false belief, Anos and Lay planned to reveal the truth about Avos Dilhevia during the Demon King Reordination Ceremony, while conducting a story on how Hero Kanon and the true Demon King fought together to defeat the fake Demon King.

But that changed when a true Avos Dilhevia appeared. At the Demon King Reordination Ceremony, the two announced that with the defeat of the Great Spirit Avos Dilhevia, and subsequent reincarnation into the kind spirit Misa, the people would no longer have to live in fear awaiting the return of the Demon King of Tyranny.