But that didn't really matter to him. He didn't need to go through all that trouble; all he had to do was choose a suitable Magic Spell and cast it repeatedly. Under the effects of his special talent, Magic Spells could be used over and over again.
For example, there was one Magic Spell that could accelerate wound healing, optimize the heart's structure, and reduce organ rejection. In the hands of other Wizards, this Magic Spell was rather useless. It seemed versatile, but in reality, it couldn't do anything well.
Its effects were too weak, and it could only be used once.
Therefore, it needed to be combined with casting many other Magic Spells.
But Isaac only needed this one Magic Spell. As long as he kept casting it, the effects would stack up, dramatically increasing its efficiency.
Of course, this wasn't to say that other Magic Spells were useless. On the contrary, the wide variety of spells made Isaac quite covetous. With the proper use of these Magic Spells, he could do much more than just transplanting hearts...
'But that's all for the future. Haste makes waste. I have to take things one step at a time. First, I need to master the Heart Transplantation Surgery.'
Isaac first selected a few of the more comprehensive Magic Spells. He then got up, walked to a corner, and brought out two gray rats, one large and one small. After knocking them unconscious, he tied them one by one to the operating table. He checked his tools once more, put on a pair of rubber gloves, took two deep breaths, and instantly slipped into his work state.
In the laboratory, Isaac carefully shaved the fine fur from the rat's chest area, so as not to affect the precision of his incision.
Isaac had done this sort of thing many times in his previous life, so he was very skilled. Even in a new body, he adapted quickly.
The rest was simple: cut through the skin layer by layer, then carefully remove the heart. Throughout this process, he also had to cast healing Magic Spells.
The conditions now were nothing like his previous life. Without the aid of Magic Spells, the rat would just die, and the heart's viability could not be maintained.
Fortunately, the healing Magic Spells were very simple, all of them basic. He had memorized the relevant Spells long ago, and even though this was his first time casting them, it went extremely smoothly.
However, just as he set down the extracted heart, Isaac froze. 'Damn it, I was too focused on the procedure and got the order wrong. It doesn't matter if the donor rat lives or dies. Why did I waste Magic Power on it...?'
"Tsk."
Shaking his head, Isaac casually cast a life-sustaining Magic Spell on it. 'A basic spell like this doesn't consume much Magic Power, anyway. I'll just treat it as a control experiment, to see if a demonized body affects the heart in return, and by how much.'
After stabilizing the Demonized Rat, Isaac turned his scalpel to the other subject—the ordinary rat that needed the heart transplant.
The entire process was as smooth as flowing water, utterly without a hitch. Before long, two rats, an emptiness in their chests, lay peacefully side-by-side on the operating table.
They were asleep, of course. Under the power of the Magic Spells, they wouldn't die so easily.
This made Isaac secretly marvel at the power of Magic. 'If I'd had this skill in my previous life, how many people could I have saved?'
Shaking his head, Isaac collected himself while cleaning his scalpel. 'Now comes the most critical part of the Heart Transplantation Surgery. There's no room for the slightest mistake!'
Even though his subject was just a Demonized Rat—the kind you could buy a hundred or two of for a single Gold Coin—Isaac would treat this surgery with the utmost seriousness.
This was his professional code as a doctor!
What Isaac failed to notice, however, was that as he concentrated on the surgery, the progress for Divine Hand on his panel was increasing at a blistering pace...
Truthfully, Heart Transplantation Surgery is incredibly difficult. In Isaac's previous life, the technique was already quite mature, but as everyone knows, a mature technique isn't necessarily an easy one to learn.
Especially since Isaac's studies in his past life hadn't been in a related field; his knowledge of Heart Transplantation Surgery came only from watching a few videos and reading several papers, without ever having studied it in-depth. Thus, even with the help of his Golden Finger and Magic Spells, his first attempt still failed.
The rat receiving the transplant died before Isaac could stack the effects of the Magic Spell.
'Still too clumsy.'
But Isaac wasn't discouraged. He reflected for a moment, identified his procedural errors, then grabbed another pair of rats and started all over again: shaving, extracting, transplanting...
And so, with the selfless sacrifice of one rat after another, Isaac's proficiency with Heart Transplantation Surgery grew, as did the progress of his Divine Hand.
Finally, after the sacrifice of twelve rats, the thirteenth successfully survived!
After receiving the Demonized Heart, the ordinary rat underwent a visible transformation. Its fur grew rapidly, and its entire body grew a full size larger!
The faint contours of muscle became visible beneath its fur. Its teeth and claws grew sharper, and it looked even more ferocious than a normal Demonized Rat!
Its tiny, bead-like eyes were filled with a crimson glow!
It also grew more violent, letting out a series of hisses at Isaac. If its limbs hadn't been bound, it looked ready to lunge forward and bite him.
And at the very moment Isaac completed the Heart Transplantation Surgery, the progress for Divine Hand on his panel reached 100%...
"BZZZZZZ—"
In an instant, a buzzing rang through Isaac's mind. Time seemed to have been paused. He could clearly see the fur on the Heart-Swapping Rat freeze in place; it was frozen mid-hiss, its heart no longer beating. In the entire world, it seemed that only Isaac's own consciousness could still move...
"RRRRIP—"
Then, the sound of tearing flesh suddenly erupted. Wisps of an unknown, purplish-black aura drifted out from the nape of Isaac's neck, coalescing moments later into a hideous, purplish-black Demon Claw!
The Demon Claw was skinless, clearly revealing its muscle fibers, tendons, and blood vessels. One end was connected to the nape of Isaac's neck, and it grew larger as it extended outward. It ended in a gigantic hand with five sharp fingers, a single palm larger than Isaac's entire body!
Once the hideous Demon Claw finished materializing, time resumed its flow.
Isaac stared at the Demon Claw in amazement, not a trace of fear in his eyes. After all, this was his own power, something he could completely control. Furthermore, he could feel a sense of affinity emanating from it.
Yes, the Demon Claw—or rather, the Divine Hand—possessed consciousness. The Divine Hand was an Existence akin to a Magic Pet, capable of assisting a Wizard with Casting.
The type of Magic Pet awakened depends on the ritual performed to become a Wizard. Isaac's Divine Hand was one of the more classic, ancient types.
At its final stage of development, it could possess power rivaling that of a Demon God!
'But that's still a long way off.'
"HAAA... WHOOO... HAAA... WHOOO..."
Although Isaac was curious about the power of his Divine Hand, the surgery wasn't finished. There was still a Demonized Rat waiting to be implanted with an ordinary heart. He took two deep breaths, forcefully suppressed the roiling emotions inside him, and continued the operation.
Fortunately, he now had a successful attempt under his belt. Furthermore, having become an Official Wizard, his Magic Power was stronger, which greatly improved the effects of his Magic Spells. Before long, he had successfully transplanted the ordinary rat's heart into the Demonized Rat.
However, compared to an ordinary rat receiving a Demonized Heart, a Demonized Rat receiving an ordinary heart showed no beneficial effects; in fact, it grew even weaker.
This, however, was within Isaac's expectations. He placed each of the two Heart-Swapping Rats into a separate cage, added some food, and only then washed his hands and stepped aside to examine the power of his Divine Hand.
"RRRRIP—"
The sound of tearing flesh rang out once more as the hideous Divine Hand emerged from the nape of Isaac's neck. It first stretched its menacing fingers, then affectionately rubbed the back of its hand against Isaac's face, just like a puppy.
Smiling, Isaac placed his own hand on the Divine Hand, carefully sensing the Talent Witchcraft that had been born alongside it—Flesh Conversion.
It was just as the records had described; the awakened Talent Witchcraft truly did have a synergistic effect with Heart Transplantation Surgery. The effect of Flesh Conversion was quite simple: it could directly transform flesh infused with Magic Power into a living biological form that possessed a degree of vitality!