An artery is a hollow blood vessel.

This simple explanation allows one to understand why an artery, built layer upon layer, is practically useless.

Fengyu knew this from the start but had no other option than to heal it like this.

If he healed the whole artery right away, he could already imagine the difficulty in doing so. Each little millimetre would have to consider the whole radius of the artery, the weight would be higher, the possibility for deformities would be extremely high...

’Deformities-’ a light lit up in his eyes when he looked at the healed artery in front of him.

’When I healed this artery, I thought it would be easier. As long as I made sure the main artery had no significant difference to the previous artery, there would be no issue. But when I opened up the artery layers around it, I somehow felt a hidden vitality inside the artery I just healed, assisting the recovery...’

His mind jumped from one matter to another, a sense of confusion welling in his mind.

Initially, he planned to simply complete the step he intended to... now, he thought that if he did that, he would lose something important.

What he might lose was less important than why he would lose it, so he focused on the things that popped up in his mind, trying to connect them with widening the tunnel...

"This is it!" Fengyu suddenly realised something -

Whenever you talk about healing or medicine, there is always the saying that every pill has poison. In medicine this can indeed be taken as a conclusion - every technique, every healing and every supplementation contains poison.

Looking at his own healing, and even at the image...

It was a pure one-sided healing that didn’t consider the harm that healing could bring.

’Cell division is a highly controlled and regulated matter of the body. Healing the body has different approaches. Recovery means that anything the body can naturally recover will be accelerated and improved.

My path of healing, using the acceleration of cell division to achieve this effect, can be said to be one of the most core ways to heal anything recoverable. But... the body’s own mechanism has the least danger in the safest environment.

Outside influence isn’t a simple 1x1 equation - normal cell division varies based on which kind of cell it is, but the division of the most common skin, flesh and organ cells usually happens in 12-72 hours. Muscle and others require a lot more. I read about this in the past to know how long it would take for a small cut to recover, and now...’

Fengyu was more and more delighted at his own vast interest, leading him to know a lot of superficial knowledge in various fields.

His mind returned to the issue, ’Let’s say the body is regulated for the division to happen in 12 hours. What happens if this instead happens in 1 hour? How will the body accept it? And my spell isn’t precise enough... will the cells only be divided where I want?’

Fengyu looked deeply at the wound, inspecting it once more. This time, he looked directly at the outer layer of the artery, inspecting it deeply.

"This is?" he asked in surprise when he saw a thin layer of skin forming right beneath the artery, something he had ignored until now...

’Skin, this is really skin! Why would skin form where flesh and muscles should be?!’ Fengyu looked at it again and again, shocked.

For the first time, he didn’t know the cause of something in front of him.

He inspected it again and again, trying to see and make sense of what was in front of him.

After a long time, he could only conclude - ’This is the danger that comes with accelerated cell division! I made a mistake. I simply accelerated cell division, thinking that was the correct path. But I never considered - why was the body not accelerating on its own?

It had reached a stance of perfect balance, and I, doing something so rash, actually destroyed the balance and created the opportunity for something like this to appear...’

Fengyu was deeply regretful, but at the same time, he was grateful that he was rather careful and that while the damage was done, it wasn’t huge.

’I, I’ll have to try to solve the issue...’ Fengyu felt insecurity for the first time in a long while.

His mind whirred, his blade moved fast as he cut off the skin, eyes focusing on the artery left behind.

Huuuuuh

Exhaling a deep breath, Fengyu calmed down. The skin tissue wasn’t thick and the artery was fine after removing it, only requiring a short time to recover.

He moved along the artery, inspecting it for any other issue...

...

Several days passed as Fengyu solved the small issues that seemed endless. Initially he hadn’t seen many, but when he used his spiritual power to inspect every single bit, he found that there were many issues.

If left unattended, they would cause small issues and lower the capacity of the artery, which would go against Fengyu’s intentions of a 100% recovery.

Fortunately after realising his mistakes, he was able to take care of them.

What worried him was... the fact that he had treated several wolves with this technique already. The small cuts were fine, but the large injuries...

Suddenly, he felt like he had participated in animal testing and then moved on to human testing, only to realise he had made a mistake, corrected the human testing experiment but neglected the animal testing part.

A feeling of sourness appeared - the sourness of realising you made a mistake that you can’t correct. At least not now.

For his own mind’s sanity, he planned to search for the wolves when he had time - likely after the Beast Tide - and if they survived, he would plan major surgeries to help them recover fully!

While his mind was focused on this, he had moved on to widening the arteries’ blood tunnel.

This required carefully scraping at the walls of the artery. Such a process was also extremely painful, but fortunately, with his experience, this part was a bit easier except that it took a whole month to complete it.

...