Slowly, Leo awoke to acid eating through his clothes. "Where am I?" Leo asked. The image of the giant jaws devouring him flashed into his head. The Deicide had swallowed him, and now he must be in the belly of the beast.
Using what mana Leo had remaining, he used the move stone skin to create a barrier from him and the stomach acid. In the corner of his eye, Leo spotted a stone tablet surrounded by mana sphere. He spotted an artifact spirit on top of the slab after treading his way through the stomach juices.
The spirit was a small spirit that looked similar to a goose. The spirit animal had a small mana shield around it. When the creature spotted a human coming towards its direction, it wondered what he was seeing was real, then it realized this was its opportunity to break free.
"Hey, you! Come Here."
"Is that bird talking to me?" Leo asked himself.
"It looks like the demon swallowed you too. If you can help me get out of here, I will give you a surprise."
The spirit had been swallowed many years ago. When the world's mana disappeared, the Catastrophe demon, known by others as the Deicide, crash-landed on Duat and began attacking each city for cultivators and artifacts. Without mana in the air, the devil couldn't traverse long distances without mana.
The cultivators without mana and cold weapons couldn't penetrate the devil's hide. Slowly many cultivators and items were devoured, giving the Deicide enough energy to move to the next city.
After attacking several cities, the demon descended upon the City of Geb. The Pharaoh and the spirit devised a way to finish off the massive beast.
The Tomb of Geb which the goose was a spirit for could absorb massives amounts of mana. The Pharaoh convinced the bird he would toss him into the mouth of the beast and from within the goose could consume its last remaining bits of mana leaving it motionless.
On the eve of the devil's attack, the Pharaoh tossed the slab with the spirit down the demon's throat. Once inside, the spirit started to absorbs the creature's mana. In most people's and monster's bodies, the dantian was close to one's stomach. This fact is what allows people to absorb mana and energies from things they consume.
Once one broke into Core Building realm that dantian became a core, but the problem was the way people and monsters leveled up past this point. In the next level of shattering, people dissolved their core while monsters fuse their core with their heart. When entering the Avatar and Construct phase, monsters would use their new heart to allow them to transform into their Avatar state and then into their Construct state.
Slowly the beast's heartbeat slowed down to a complete stop. This action signaled it had no more mana to keep it beating. The saddening part after this is that the Pharaoh never came for the spirit. Since that day, it spent trapped inside the beast.
Seeing no option, Leo agreed to help, after the bird retold his story and explained the Deicide weakness. All Leo had to do was tear through the stomach to the beast's heart and destroy it.
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Back at the ruins with the demon gone, the lion rounded up the cultivators. "We need to go after Leo." Green Tooth said to the group.
The two disciples of Green Tooth's nodded their head in agreeance. The three of them then looked to the mermanian pair. Geph spoke up, "I owe that human my life. Let us go after that beast." Sepha nodded her head in agreement. The peggian hadn't returned, so they decided to leave without him.
The five of them loaded into their craft and left eastward in the direction the Deicide chased Leo.
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Leo equipped his mace and began to attack the Deicide's stomach lining. Without using mana, it was difficult, but the spikes on the Stone Breaker acted like a cheese grater upon the beast's gut.
"AHHHH BUG UPSET MY STOMACH!"
Reaching out both paws the beast smashed his stomach on both sides. The Deicide's innards were all crushed squishing Leo from both sides. Leo could feel even more bones inside him snap.
"Ahhhhh!" screamed Leo. As his stone skin shattered and acid attacked Leo's skin and injuries.
"Keep attacking before you succumb to your wounds." The spirit bellowed.
Leo pulled out all of his gemstones and absorbed their mana. Then with his broken arm re-enforced with mana, he executed Meteor Stick Dance. The lining was ripped apart as Leo attacked his way to the heart. Blood and guts covered the boy as he attacked.
"AHHH, BUG HURTS!!!" The Deicide crashed into a nearby mountain in pain. Since ancient times, this death beast had never been in so much pain. It didn't know how to deal with the situation calmly even though it was at peak Construct level.
With a swing of his mace, Leo punctured the beast's lung. The wind blew Leo back into the stomach, crashing into a pocket of blood and acid. The skin on Leo has mostly eaten away, leaving a lot of muscle and bone showing.
Losing all momentum, Leo couldn't use Meteor Descent to attack with but looking up he could see the beating heart. Feeding all his mana into his mace, the skinless man tossed Stone Breaker towards the beating organ.
Stone Breaker lived up to its name and crashed into the heart, piercing it in one fell swoop. This final attacked caused the Deicide to breathe its last breath. "BUG..."
The giant Deicide collapsed to the ground, finally dying after a millennium of causing terror. Blood oozed from every orifice of the creature.
The stone slab floated over to the dying Leo. The bird gave Leo a weird smile. "Thank you for killing this beast and unleashing from my prison." It paused and looked at Leo gasping for air. "But you shall stay in this prison that I was left in for centuries."
After all these years the spirit came to resent humans for the Pharaoh sacrificing him. The spirit and artifact floated out of the Deicide's mouth to someone staring at him.
The spirit scanned the humanoid and nodded in approval. It had the same resentful aura the stone slab had. "You have been used as a tool all your life. Allow us to join hands and rule."