And now, he had actually obtained a level-five high-grade cultivation technique, and it was even a body-refining technique.

Body-refining techniques are even more precious than qi-cultivating techniques of the same level, because body-refining techniques are extremely rare.

Body-refining techniques are the true methods for strengthening the physical body, while the body tempering stage before the Qi Cultivation Realm is merely basic physical training.

The Mark Sutton family only has two body-refining techniques, but very few young disciples practice them, as the progress is slow and it takes too much time.

For the young disciples of the Mark Sutton family, the primary goal is to improve their cultivation and increase their strength.

This ""Universal Divine Art"" is even more precious than that Spirit-Slaying Sword.

Whew!

Taking a deep breath, Mark Sutton looked at the other three manuals.

Compared to the Spirit-Slaying Sword and the ""Universal Divine Art,"" the other three manuals were much more ordinary.

All three manuals were level-three low-grade, consisting of a sword technique, a movement technique, and a cultivation method.

Although these three manuals were not as good as the ""Universal Divine Art,"" they were still many times stronger than those in the Mark Sutton family.

Coincidentally, these were exactly what Mark Sutton needed.

As for the remaining pile of milky-white crystals, Mark Sutton didn't know what they were, but he could sense a vast amount of spiritual energy within them and was certain they were treasures.

After a while, suppressing his excitement, Mark Sutton put away the other manuals, leaving only the ""Universal Divine Art.""

He carefully read through it, memorizing the formulas and key points.

This underground world was safe and quiet enough, so Mark Sutton sat cross-legged on the spot, released his Martial Spirit, and began to cultivate.

The Universal Divine Art is a technique that tempers the body using the spiritual energy of heaven and earth, or one's own true qi. It is extremely profound.

At this moment, the true qi in Mark Sutton's body transformed into runes in the shape of ""elephants,"" constantly drilling into his flesh and blood, tempering his body.

An hour later, Mark Sutton suddenly opened his eyes, his face full of surprise.

""This technique actually consumes so much true qi?""

After just one hour of cultivation, the true qi in Mark Sutton's body was completely depleted.

Next, Mark Sutton could only do his best to activate his Martial Spirit and absorb the spiritual energy of heaven and earth to temper his body.

All the spiritual energy he absorbed transformed into runes and merged into his body.

Mark Sutton's body was like a bottomless pit, frantically absorbing the spiritual energy runes.

Time passed quickly.

He cultivated like this for eight days. During this time, whenever Mark Sutton was hungry, he would catch a few fish by the dark river to fill his stomach, so food was not a problem.

On the sixth day, Mark Sutton successfully cultivated the first layer of the ""Universal Divine Art.""

After mastering the first layer, Mark Sutton's physical strength increased dramatically. Relying solely on his body, the power of his punch exceeded the strength of three tigers, making him even stronger than a third-level Qi Cultivation martial artist.

For Qi Cultivation martial artists, each level increases their strength by the power of one tiger.

The strength of one tiger is about five hundred jin, so three tigers is fifteen hundred jin.

Mark Sutton felt that his current strength was close to two thousand jin, which is the power of four tigers. Even if it wasn't quite four tigers, it wasn't far off.

After just a few days of cultivation, his strength had skyrocketed, which only strengthened his resolve to master this technique.

If he could cultivate this technique to above the tenth layer, not to mention the small Lin Yang City, he would be unrivaled even in the entire Tianyue Kingdom.

However, after mastering the first layer, when cultivating the second layer, Mark Sutton clearly felt that the progress was ten times slower than when cultivating the first layer.

It only took six days to master the first layer, but to fully master the second layer, Mark Sutton estimated it would take at least two months.

Therefore, after cultivating for another two days, Mark Sutton stopped his cultivation.

He had been out for ten days already; it was time to return.

After restoring the true qi in his body, Mark Sutton buried the golden skeleton and left the underground world, rushing toward Lin Yang City.

The storage ring of the golden skeleton had given Mark Sutton a great opportunity, so Mark Sutton decided to let the owner rest in peace.

On the way back, Mark Sutton suddenly thought of a problem.

Because cultivating this ""Universal Divine Art"" requires a large amount of spiritual energy, and the further he goes, the more spiritual energy is needed.

If he continued to cultivate this technique, all the spiritual energy absorbed by his Martial Spirit would be completely consumed.

His own true qi would no longer increase, and his cultivation would not improve.

Moreover, if he practiced both qi cultivation and body refinement, the speed of progress in both would be greatly reduced.

""Should I give up qi cultivation and focus solely on body refinement?""

As soon as this thought arose, Mark Sutton immediately dismissed it.

For others, practicing both qi cultivation and body refinement might greatly hinder their progress, but for him, it was not a problem at all.

His Martial Spirit could be upgraded.

As long as he raised the level of his Martial Spirit, the speed at which he absorbed spiritual energy would greatly increase, and his cultivation would naturally improve rapidly.

Now that his Devouring Martial Spirit had reached human level, third rank, its absorption speed was ten times faster than at human level, first rank.

If he could raise his Martial Spirit by a few more ranks, his cultivation speed would surely skyrocket again.