Gerald made a grin and welcomed the attack. The Lion tried to take him down in the first jump, but Gerald leaned forward and welcomed the attack with open arms.

The beast and man collided, both not suffering any injury. Gerald grabbed the Mountain Lion, spun around, and threw him to the side. using the momentum of the beast's assault. He was using both defensive and strengthening magic, the Juggernaut, making him extremely strong and difficult to deal with.

He then threw himself on the animal, knife in hand. He stabbed it down with all the weight of his body behind it.

They rolled on the ground, and the beast tried to bite his hand, but it had the same effect as if trying to bite into a rock. There were some white scratches left on Gerald's arm, but that was about it.

The blade struck the Mountain Lion's chest, right above the heart. But the beast was strong, and the rib cage was in the way, so it was still safe.

However, Gerald suddenly increased gravity on himself, making his body twice as heavy. Putting all his body weight on the knife's handle, it easily broke through the defense of the Lion and stabbed through the heart. Giving it a quick twist, the wound increased, and when he pulled it out, a fountain of blood gushed out.

Gerald jumped off the dying Mountain Lion and waved his hand in the air. The blood immediately froze in space and then quickly moved to a container he prepared specifically for this occasion.

The death was swift and merciful, the beast died in seconds.

"Your life was not in vain, I'll make good use of it."

The other male Mountain Lion was shocked and it hesitated for a second. It was clear to it that this human was dangerous, but it had a potential mate watching.

Roar!

Steeling its resolve, the Mountain Lion rushed forward to attack.

"Tsk," Gerald clicked his tongue, "Why do you beasts always like to rush towards your death?" He then slightly moved his finger and a Stone Wall rose from the ground right in front of the charging beast.

Bam!

"I'll play with you later, just be patient!" Saying that, Gerald grabbed the dead Mountain Lion and swung it on his back. "Ugh, it's heavy…"

He was slightly overburdened, but luckily he had anti-gravity magic. He just had to use more Mana to increase the size of the warped space around him and he could fly again. Just as the Mountain Lion recovered from a painful crash into the wall, Gerald rose into the sky and flew away.

The beasts stood there watching him leave, but there was nothing they could do.

"Hmph, cowardly human, I'll let you go this time!" the male Mountain Lion said and turned around towards the female proudly. Although it clearly lost the fight, it was still the winner in the end.

Gerald flew above the forest and soon found a clearing where he could land. He tossed Lion's carcass to the side and stretched his back. The beast was large and he needed to find a safe place to process it. One carcass was enough for now and killing more would be wasteful, so he left those two alive.

Besides, he could go on another hunt later if he needed to do more experiments.

He utilized his powerful magic to reshape the place. The ground rose and green grass and flowers were replaced by solid stone. The floor split apart and walls of solid rock rose four meters up all around the place. A stone table was formed in the middle under the Mountain Lion and a seat grew right beside it.

After the shelter was completed, Gerald took his knife and got to work.

He decided to remove the intestines and skin. Although it was not required for the Essence Extraction, it was still recommended for those that were only just learning the skill.

After he was done, Gerald sat on his chair and cleared his mind. He followed the instruction in the book and focused his magic on the beast.

The carcass started to twitch at first, but soon it started to shake. The flesh expanded and started to slowly tear itself apart.

This all took a few minutes to happen. The concentration made Gerald frown as he already started to feel some discomfort. The skill didn't use much Mana, but it was extremely focus-intensive.

The floating flesh started to slowly disintegrate into dust, and only tiny specks, like black grains of sand, remained. Gerald observed, with great interest, how the flesh turned to dust and was then scattered by the wind.

All those tiny black grains were slowly pulled together and gathered on his palm.

When it was all over, it was all compressed together, forming a pea-sized black sphere. It was quite hard with a smooth surface, almost like a black pearl.

"Hmm," Gerald frowned. He flipped through the book to see the description of the final product again just to make sure.

"Okay, so according to this book, this is the lowest grade Essence... and about the lowest fraction of Essence Extraction…."

After he finished reading the description, Gerald sighed. The amount of Essence he extracted was about 1-2%. The sizes went approximately like this: Pea-sized, cherry-sized, walnut-sized, chicken egg-sized…

And that was for the Class-One beast. Gerald wasn't sure of the exact measurements the book used, but the human was considered Class-One, and so were the big cats such as lions and tigers.

Class-Two would be a Silverback or a horse, maybe even an elephant. It was all dependent on size.

Anyhow, the Essence Gerald extracted was considered extremely underwhelming. The book said it was basically worthless because it was not worth the effort of extraction, nor was it worth absorbing.

It was just too little.

"Huh, so, if I guess the Mountain Lion was Iron Rank-5, then this black marble can increase my strength by 5-10kg?" Gerald scratched his head after a quick calculation. "How is this not worth it? What kind of crazy strong being made this book to consider this a waste of time?!"

He spent about three hours in total to get this black bead. Even if he spent the entire day, gaining this bit of strength would still be worth it for him.

He took some time to confirm the process of absorption before testing the effects of the bead. After he was confident he understood it correctly, he made himself comfortable in his seat and swallowed the bead. The book specifically warned not to let the bead be digested, he had to break it down with his own internal energy and absorb it into his flesh.

He closed his eyes and focused all his attention inside his body on the black sphere. He had to concentrate on it hard and follow the instructions in the book to break it down.

The bead started to fall apart as it appeared to be melting. It became softer and then turned to a fluid and started to spread from his stomach outward.

Wherever it went, Gerald felt some changes happening, although he wasn't sure what exactly. A sort of warmth spread across his body to every bone and muscle, to every vein and capillary, to the tendons and skin. After an hour the feeling came to an end and Gerald also stopped controlling it.

He couldn't feel any black bead liquid left.

But according to the book, it would still take about a day for it all to spread equally across his body and stabilize. Until then he should not consume more Essence Cores or it might be too much for his body to handle.

Gerald wasn't sure if this warning applied to the lowest rank of Essence Cores as well, but it wasn't like he was in a hurry. He could just test it out slowly. He didn't think this tiny bit of Essence could hurt him anyway.

"Well, if I can manage to get a higher Essence yield from these beasts, I might be able to form a cherry-sized, or even walnut-sized bead next time! I could increase the strength-gain two to five times!"

According to the book, the highest extraction yield you could get was just below a fifth of the strength that the target had when alive.

Gerald didn't even dream of reaching that height, since he didn't even have a clue how to upgrade the 'rank of his energy' as the manual required. He just wanted to improve a little bit, just enough to make his effort worth the time, according to the book.

That would be at making the Essence Core reach at least the size of a walnut. In terms of rough numbers, that would be around 8% Essence extraction.

"Practice makes perfect, they say. Let's see how much practice I will need then…" After finishing his rest, Gerald decided to go on a hunt again. He still had a few days to spare, so he decided to do his best before returning to the capital.

He did not go on a killing spree like usual, instead, he only hunted one animal at a time, usually somewhere in the middle of Iron Ranks so he didn't have to try too hard. He would kill and then return to his encampment and refine the carcass as the book said.

Each cycle took anywhere between two and five hours, so he couldn't do it that often. The concentration required for the process was immense, so he also needed to take a rest once in a while.