With the Marrow seething in Lin Mu's stomach, the obscure runes quickly covered it. The runes kept on increasing in number and soon formed into rings that surrounded the stomach, insulating any of the energy from escaping it.
This was really important and would prevent Lin Mu from losing the efficacy of the marrow too.
Lin Mu recited the Mnemonic of the Tyrant Bull Marrow secrets, while keeping an eye on the energy waves of the marrow. He needed to first get used to it, so that he wouldn't lose focus when he started the next step.
He stayed like this for several minutes, adapting to the energy signature of the Marrow.
'An extra step I need to take due to having a bloodline assimilated already,' Lin Mu thought to himself.
If one didn't have a beast bloodline assimilated, they wouldn't have had to do this step, as their bodies would not be clashing with the marrow. But in Lin Mu's case, he already had the bloodline of the Great Slumber bear which could compare to the Tyrant Bull.
The marrow of a beast had dense bloodline essence within it, thus it was very easy for it to be mistakenly taken up by the body as an attempt at bloodline assimilation.
Though it was rightfully so too.
After all, from what Lin Mu could tell, the Tyrant Bull Marrow Secrets may as well be a technique to assimilate the bloodline, but it diverted it into another method.
This method was rather unique and was to condense a totem on one's body. Instead of letting the bloodline be fully assimilated. And doing that was not easy, as the body had a tendency to take it within it, instead of isolating it.
Or even if it couldn't take it, the body would rather reject it than keep it isolated.
This was where one needed a great control over their body, a strong will to withstand the pain, and a tough body to endure it all. If one missed even one of these, they would simply die from the overbearing Tyrant Bull Marrow.
This was the reason why so many considered the Tyrant Bull Marrow a dangerous material and why so many immortals died using it.
Even with the Tyrant Bull Marrow Secrets technique within one's grasp, they were not guaranteed to succeed.
Finally, when Lin Mu felt like his Bloodline of the Great Slumber Bear was fine with the marrow and was not going to target it, he proceeded with the next step.
"Refine the Marrow, Condense the essence, raise the spirit!" Lin Mu chanted the Mnemonic.
In the next second, the marrow within his stomach was rapidly digested, turning into pure energy which was then absorbed. This pure energy was none other than the essence of the marrow which contained the bloodline of the Tyrant Bull!
This was why Tyrant Bull Marrow Secrets seemed so much like a bloodline assimilation technique. Even this step was similar to that. Except, the fact that the Bloodline was refined in the body itself than externally.
But that was not all, as the refinement of the Tyrant Bull Marrow was not a simple process. For many people, it would take hours if not days to refine it. But Lin Mu had a great advantage here in the form of his Stomach.
The stomach that was transformed from the Unknown Technique of the Lost Immortal rapidly converted the raw marrow into pure essence. Lin Mu fully focused on it and guided this essence to his Dantian.
It was not an easy task, as the essence was rather overbearing. It tried to gnaw at his meridians, tried to tear them and burst out of them. But to Lin Mu, this was something he had already gone through before.
His meridians were like Fine Steel Walls, unable to be damaged even by cannon fire!
The essence raged within his meridians, but was unable to escape. Lin Mu channeled it into his Dantian and made sure not to let even a single wisp of it go astray. This process was fast due to the essence's properties and due to it raging.
Lin Mu simply used his own immortal Qi to force it to enter the Dantian.
It was similar to using high pressure water to push out stuck sand from a clogged pipe.
All of the essence was pushed into the Dantian, and finally dropped into the ocean of Immortal Qi. Here, it was as if it molten lava had met water. The immortal Qi sea bubbled up, as if boiling from the raging essence.
"Ugh!" Lin Mu let out a little cry, finding this pain to be rather different.
The boiling Immortal Qi was expanding and exerting more pressure on the walls of his Dantian.
'This is the step where the Immortals with a strong body but weak control fail.' Lin Mu knew. is the owner.
If one had a strong body, they could endure the marrow and even refine the essence. They would then endure the pain of their meridians being scraped and get the essence into the Dantian. But after this point, they would have to face the second trial of the process.
The boiling of Immortal Qi!
Here one needed to rely on their control of Immortal Qi in order to stabilize the boiling Qi, as well as condense the immortal Qi that had turned into vapor. The immortal Qi in the form of vapor would exert a force on the Dantian, pushing it further.
If one didn't have a Dantian that had been tempered and expanded before, they would simply explode from this. But if one had expanded their Dantian and didn't have good control over the immortal Qi, they would still exploded from the boiling immortal Qi.
It seemed like a situation of Despair, but Lin Mu's practice with several skills that needed fine control had trained him for this. Whether it be the Three Apertures Invoking Technique, the Boulder Collapsing Fist, or his Spatial skills, all needed precise control over various energies!