Slowly, he stuffed the piece of paper back under the mattress. Danny Goodwin pulled up the quilt, took a long breath, closed his eyes, and began to mentally simulate the circulation route of the "Lihuo Heart Technique" in his mind.

If it had been the just-transmigrated Danny Goodwin, even if he had obtained the complete Lihuo Heart Technique and memorized it perfectly, he still wouldn't have been able to cultivate it, because he didn't know the secret to cultivating inner energy.

But now things were different. He knew the secret. Although the Great Strength Vajra Qigong was the most basic of inner cultivation techniques, it was still an authentic inner cultivation method. Its entry point was no different from other inner techniques, and the key points were similar.

This "Lihuo Heart Technique" was clearly a level above the Great Strength Vajra Qigong, and in terms of depth and subtlety, it surpassed it by several levels. However, the key to getting started was not much different from the Great Strength Vajra Qigong.

Carefully reviewing the entire cultivation method and the inner energy circulation route of the "Lihuo Heart Technique" in his mind, Danny Goodwin had a general understanding of this technique. It differed from the Great Strength Vajra Qigong in two main aspects. The first was the route of inner energy circulation. The route for the Lihuo Heart Technique was more than twice as complex as that of the Great Strength Vajra Qigong. As a result, the time it took for the inner energy to complete one cycle was much longer, and more importantly, the increased length of the route made the control of inner energy much more complicated. With Danny Goodwin's current level of control, he could only manage two cycles at most. The second difference was the method of absorbing the primordial energy of heaven and earth. So-called inner cultivation, at its core, is about absorbing the primordial energy of heaven and earth for one's own use, drawing it into the body and using special methods to assimilate it, turning it into one's own power. This is the fundamental principle of all inner cultivation, no matter how advanced. The Great Strength Vajra Qigong is like a glutton with indigestion, swallowing everything indiscriminately, digesting poorly, and after a bout of vomiting and diarrhea, both the nutritious and the toxic are left in the body, resulting in a mixed and impure energy. The Lihuo Heart Technique, on the other hand, is different. From the very beginning of absorption to the internal refining process, it is highly purposeful. It seems to only absorb the primordial energy with a certain attribute from the heaven and earth, excluding all other attributes. The reason its internal circulation route is more complex than the Great Strength Vajra Qigong is because digesting this single-attribute energy is much more difficult than the mixed energy obtained from indiscriminate absorption.

"Lihuo, Lihuo—it's obvious that it's about absorbing the fire attribute energy from the primordial energy of heaven and earth and refining it!"

Danny Goodwin lay on the bed, opened his eyes, and in the darkness, his eyes shone with an exceptionally bright light. "Although this Lihuo Heart Technique is much more advanced than the Great Strength Vajra Qigong, it's clearly still an entry-level technique. Otherwise, a rookie like me wouldn't be able to understand it. Tyler Walker said he got this as spoils of war on the battlefield, meaning he took it from someone he killed. If that person could be killed by him, their martial arts couldn't have been that high, which in itself shows that he couldn't have possessed a truly advanced manual. Still, this is a real bargain for me. If this technique were any more advanced, I really wouldn't be able to understand it, and it would be useless to have it. If it were any more basic, it wouldn't be much different from the Great Strength Vajra Qigong. This level is just right!"

Thinking of this, Danny Goodwin smiled, suddenly recalling how, when he was a child in his previous life, teachers always liked to have them set study goals—goals that you could reach if you just stretched a little. After growing up, these so-called study goals became a joke in his eyes, but he never expected that after being reincarnated, the legendary "goal you can reach if you just stretch a little" was actually gradually being realized.

Legend has it that cultivating inner energy can strengthen the body and prolong life. In his previous life, when reading wuxia novels, Brian Walker also believed this. But in this life, after actually cultivating inner energy, Danny Goodwin knew that at least half of this rumor was false.

Cultivating inner energy can indeed strengthen the body and prolong life, but only if you have at least trained your external skills to the level of bone refinement. Otherwise, the deeper your inner energy, the shorter your life, because your body simply can't bear too much inner energy. It's like a container—when the liquid inside exceeds its capacity, it overflows. If the container is sealed, it will burst. The body and inner energy are like a sealed container and liquid; so, to hold more inner energy, you must strengthen the body. The more inner energy you have, the only thing waiting for you is a "bang"—an explosion.

The Lihuo Heart Technique cultivates pure, authentic fire-attribute inner energy, so the requirements for the body's meridians are naturally higher than those of the Great Strength Vajra Qigong.