The first step of this war was the Galaxy Protection Fog. The Empire released the fog to surround the entire Milky Way Galaxy. The main purpose of the fog was not to isolate the Gods from the outside or to prevent Guzznad from blackmailing the Empire.
Its main purpose was to isolate the space of the Milky Way, preventing Guzznad or anyone else from opening portals to other planes. With this method, the Empire effectively cut off Guzznad's support from the Abyss Plane or any other planes he may have conquered.
Without any backup and complete isolation, the Empire strikes back. The second step was to render the greatest advantage of the undead obsolete–their large number.
The Empire finally deployed clone legions.
The use of clones has been minimal during this war. The main reason is the controversy over using them as cannon fodders in war, not treating them like humans even though they have a soul.
Many people protested, asking to pass laws to stop manufacturing clones or give them the rights of normal citizens. The voices of these people were loud at the beginning of the war.
However, after countless casualties and the media manipulation of the Empire, their support quickly dwindled when the narrative changed to the fact that so many lives could have been saved if clones had been allowed to be used.
Now, with very little resistance, the Empire finally deployed clones. Undead turned all life they encountered into one of their minds, hence why they are such a catastrophe to all races and civilizations.
However, such a tactic became useless after Guzznad occupied half of the galaxy. His army was vast. Sadly, his number could not compare to the Empire's factory that manufactured clones like they were objects.
After these clones are created, a machine instills a vast amount of knowledge into their mind to increase their Soul Power. Then, their bodies are strengthened through genetic manipulation before injecting a vast quantity of mana into them.
With Edward's new enchantment and control of the Mana Grid, there was plenty of mana to go around.
So, a terrifying legion swept Guzznad's territory. Like the undead, the clones were programmed to have no fear, feel no pain, and execute all given orders. Furthermore, their souls contained seals to prevent Guzznad from turning them into undead.
In other words, Guzznad kept losing more troops without ways to generate more.
The Empire had another advantage over Guzznad's troops–technology. Myriad fleets flew to different parts of the galaxy, conquering one Star System after another.
Most of Guzznad's ships could not be considered spaceships. Sure, they could travel in space, but they did not have things like cannons, missiles, torpedoes, plasma guns, etc.
So, the Empire's tactic was swift and effective. They would bombard the planets until the undead were incapacitated and unable to move. Then, they would land and use the newly developed method to discover Guzznad's core followers through the amount of faith they released.
Most of Guzznad's core believers or followers will be executed or captured for interrogation. Meanwhile, the people he forcibly turned into undead during this war and did not have time to become hardcore followers will be captured and returned to the Empire.
Then, these people will go through rehabilitation from Bellatrix's Department, where the Death Staff will be used to revert them to their former selves.
If the process fails, the undead will still be integrated into the Empire since Wiz has been on a campaign for acceptance for all undead. By now, most people are now used to undead being a daily part of life.
With these methods and advantages, the Empire took less than two weeks to take a vast amount of Guzznad's territory. So, Edward went from controlling half of the galaxy to controlling two-thirds.
By then, the Blitzkrieg-like tactic used by the Empire had become less effective; Guzznad had responded. He used one of the few advantages he had–high-level powerhouses.
Guzznad had countless Tier 8 Undead under his control, while Edward and the Starskin Queen were currently the only two Tier 8 Arcanists of the Empire.
Unfortunately for the Death God, the Empire's tactician anticipated this possibility and prepared.
The first way to deal with this problem was sending the Tier 8 Golems. These golems were created using a large quantity of Mana from the Mana Grid and a new soul technology.
The Empire could not now raise a soul to any Tier by instilling a large amount of knowledge into it. Previously, such a soul would collapse by the time they reached Tier 5. But, now, they could maintain these unstable souls through control of their Soul Flame.
The result was these golems. Although they could only survive 3-5 years before the artificial soul collapsed, this time was more than enough for this war.
The second method the Empire used to make up for the gap in Tier 8 Powerhouse was one of Hermione's inventions.
From his Konosuba Voyage, Edward created Arcane Sparks that allowed Arcanists to condense their Karma and use it as Empowerment. After activating the spark, an Arcanist might cast a spell a Tier above their level.
Hermione–who was studying karma–created a way to gather the negative karma or sins created by the undead and condensed them into crystals. With these Karma Crystals, a Tier 7 Arcanist can use Empowerment to cast Tier 8 Spells, thus gaining the advantage in battle.
With these advantages, the Empire slowly took over Guzznad's territory. The war could not be won easily to not raise an eyebrow. So, after the previous Blitzkrieg Tactic, things proceeded slowly.
It took more than a year before Guzznad only had five Star Systems remaining, defending them as their last line of defense.
During this year-long battle, only a few interesting things occurred. The first one was Guzznad shutting off his Defensive Treasure and trying to break the fog; he failed.
The second was that the Death God finally realized the importance of technology and tried to build himself a proper fleet for this war. Alas, the Intelligence Department and Divination Sector discovered his method.
Then, Olivier's previous elite team, when she was in the military, succeeded in a dangerous mission where they infiltrated the base of Guzznad's research, destroying it before escaping.
Edward was very happy with this mission because the Ninjas participated and were instrumental in the success.
The last interesting aspect of this war was Guzznad creating three more Tier 9 clones, trying to use the number advantage to win. Sadly, Edward did not show up, as Dumbledore, Rowena, and Snape used the floating cities to destroy them.
Finally, Edward's Netheril arrived at Guzznad's last territory, ready for the final confrontation that would end this war.