When the Shadow and Rex first entered the cavern. There were about ten undead demons, and due to Rex throwing the stones, that number slowly increased to twenty-five.
Now that Rex is fighting the demons. The number of undead demons inside the cavern is at one hundred.
Rex knew he had to keep this up until the number of undead demons came to one thousand. He hoped that he, himself, could last that long. Fighting against huge armies that are humanoid and fighting against an undead army are different.
The humanoid armies will eventually either run out of Qi, mana, or fighting spirit. That is not all, if a general calls for a retreat. Even though people will stay die in the retreat, the victor has already been announced. Fighting against an undead army, the one who usually wins is the undead simply because they are already dead. They will not stop their attack until they have been destroyed by a Holy Element or their bodies are disintegrated.
Every five undead demons that Rex burnt to ashes with his axes and affinity. The spawn rate would increase the number of demons.
Each enemy that Rex kills only brings two enemies. Rex felt that this would honestly take forever. He knew that this battle was going to take a while, but not this long.
Eventually, the undead army reached the two hundred and fifty mark. The time it took was about an hour and a half. Rex knew that this battle had to quicken up.
Rex slammed the two axes on the ground.
He then yelled, "New Axe Art: Flaming Quake."
Instantly, the ground shook. The fight outside the cave felt the ground shake, but nothing happened.
The people outside were more focused on fighting each other.
A massive pillar of fire rose from the ground. Everything the fire touched, it melted or disintegrated.
Rex saw that nearly all the undead army died in the Flaming Quake. He was happy that maybe this would increase the number quickly. It did not. The number of the undead army only became two hundred and seventy-five.
Rex kept fighting the undead army at tooth and nail. He felt his being tired from fighting so much. He knew he had to for this Mistress of the Shadow.
The time now was nearly three hours, and the undead army just reached four hundred. No matter how many Rex would kill instantly or kick to another to kill. The number of enemies was not growing like it should have.
"Perhaps it is because the Necromancer is summoning also. This would be a great time to finish and fight the whole horde outside." Rex thought.
"Do not push yourself with that. Just keep them fighting here. The necromancer can not summon at both places. He is using very little Qi to keep this place summoning." A voice told Rex.
Rex continued the fight like he had been. He figured he had already killed more than five thousand give or take. That was due to using his new Axe Art multiple times.
Now we are nearing the six hour mark, and the number of enemies is at six hundred and fifty.
Rex was exhausted. He used his new Axe Art so many times that his Mortal Qi was about gone. He did not want to use his Heavenly Qi or Godly Qi.
Rex focused on his Body Cultivation Qi. He stood in front of the undead army. He continued to hack and slice through the army.
Outside the cavern
"Who in the name of Hell is keeping my army at bay?!" The necromancer thought.
The Mistress seemed pleased that the undead army had not come from the cavern.
When she heard that a mere Mortal Cultivator had been tasked with helping her. She laughed, but seeing the fight inside the cavern had lasted six hours. She was pleased.
"Perhaps I will pleasure him when he exits." The Mistress thought.
She and the necromancer kept fighting.
Back inside the cavern
Rex continued this one-sided brawl for another six hours. Finally, the time came when Rex reached the summoning pillar.
"Maybe I will max it so the necromancer will tire out easily." Rex looked at the pillar.
He had no idea about the pillar. It was covered in Demonic Language.
Rex had no choice but to continue the fight. Nearly twelve hours into the fight. Rex heard a Ding.
Rex checked his notification.
"Congratulations, the Legendary Axe Soul has become Mythical Axe Soul."
"Due to the Demon's Soul inside the axe, you have acquired Demon Knowledge."
"Demon Knowledge allows you to speak, hear, and write Ancient Demon Language."
"Demon Knowledge allows you to speak, hear, and write Common Demon Languages."
"Demon Knowledge allows you to speak, hear, and write Forbidden Demon Languages."
Rex had a breath of fresh air while reading the notifications. He went back and tried to read the pillar.
Rex could not read Magical Demon Language. He could read part of it, Rex could not understand most of what he was reading.
"This truly is a disaster." Rex said.
Rex knew that he had now killed over twenty thousand undead demons. Due to him using the Legendary Axe Soul. Now, he did not want to continue this game of cat and mouse against the undead army.
He had killed more than what was needed for the Quest. He had not faced against a full one thousand army yet. This truly made him mad.
Rex finally reached the thousand army mark, nearing the twenty hours' worth of fighting. This made Rex truly happy.
He instantly whiched his axe and used the whirlwind technique. Once the whirlwind hit the pillar, it completely destroyed it. Along with every undead demon.
That was not the end of it. The whirlwind pushed itself out of the cavern. Due to it being a special attack from having the axes together, there was no Qi involved.
The necromancer noticing the pillar had been destroyed. Tried to enter the cavern, but the whirlwind pushed him back out and hurt him.
Although the necromancer was not pushed far. What he saw was a white robe and two extremely large axes standing outside the exit of the cavern.