(Author's note: This series of chapters will mark the end of the first arc, so have fun reading I guess. Also, this is going to be a really really long chapter.)
'Right, my appearance is of a teenage boy with blonde hair and scarred skin. Who is this weirdo?'
Jane was kneeling on the floor, packing whatever little clothes he had into a quickly conjured bag. His brother was presumably doing the same thing, although he may have had some other keepsakes to bring along.
He stopped for a second, then looked at the books of both runes and of anatomy his teacher had lent him.
'I'll have to give those back to him next time.'
He sighed for a bit, then recalled the contents of the book. Then, he cleared out an area of his room and formed a thin insulating layer. With this, he was ready to get to work.
From his pocket, he fished out a small fragment of bone. He used to harvest these from himself every time he needed to experiment, but the process was both painful and a waste of time. Thus, he began saving the bones from his experiments for later use. This one was kept alive using 'Breath', but unable to grow or heal itself further. That would change soon. In preparation, he took a small knife from his bedstand.
'My sweet child...'
Jane had sharpened this knife obsessively in order to further his experiments. Indeed, without even applying pressure, anything it touched would be inflicted with a tiny wound. The edge of the blade glinted back at him. It was time to start.
Jane manifested a few 'Breath' runes, and enclosed them inside an 'Include' acting on his workspace. Then, he used a combination of 'Flesh' and 'Grow' to form a blob of flesh. He looked at the sagging, bright-skinned mass for a second. Infinite possibilites lay just beneath it's surface.
With surgical precision, Jane began cutting the mass apart. He identified all of the different strands of muscle, and cut them apart according to their direction. The nascent organs were set aside in a neat pile. Connective tissue was carefully removed from the surrounding flesh and laid in a separate region. Larger nerves were isolated, as well. Before long, Jane had completely deconstructed the mass of flesh he created.
'Should I try that, this time?'
Jane thought for a moment, then chopped his wrist off. Harvesting flesh from his fingers would be much more painful than just having his hand missing, after all. Wasting no time, he sliced out a portion of his thumb's nailbed and healed the resulting wound. The nail looked a little misshapen now, but it was fine. Even if Jane could form something that looked like nails already, it would be much more difficult to actually make functional ones. Thus, he chose to harvest his own, already-functioning nailbed.
After reattaching his hand, Jane got to work. Using the flesh to grow the fragment of bone he kept, planning out the functions...
Once the bones and joints were attached to the muscles, Jane overlaid important bits of skin and fat on, and relied on 'Grow' to form the rest. After it was done, he found an important nerve of his own, and cut through to it. He also made a small hole in the bone to accomodate the new appendage. Finally, he mushed together whatever looked important, and healed it all together using 'Grow'.
'Heh heh... it's perfect...'
Although it was gruesome and malformed, his new limb was a success. His control over it was terrible, but it indeed moved as it should have. The nails on the odd fingers lining what could hardly be called a hand scraped against the floor, bringing a slight pain to his unfamiliar body part. This pain was proof of his genius.
---
"My disciple..."
"What? Surprised?"
"No, no, it's just that..."
Calex looked a little embarrassed.
"I understand you, my disciple. Indeed, I was a hot-blooded youth once, as well. However, don't you think your efforts are a little... excessive?"
Jane looked down at the outline in his pants. Responding to him, his appendage wriggled slightly.
"Wait— That's not... Look!"
He started pulling his pants down to show his experiment to his teacher, but the latter turned away.
"You need to think about the woman, as well... You know, we come in all shapes and sizes, so being born like that isn't too horrible. My disciple, if you accept yourself for who you are... Hmm?"
Jane had finished undressing, deciding that it would be the least shameful option. Whatever misconceptions his teacher may have had, this would solve them.
"I experimented a little with flesh-related magic, and I started to wonder about prosthetics, so..."
He had cast a 'Reinforce Material' in the joined portion, relieving the undue stress in his femur.
"...Not bad. How well does it work?"
Jane wrapped it around his leg, and then unfurled it again. He lowered the "hand" to the ground, and picked up a clod of dirt, which he then threw at his teacher.
"About this well."
The particles of dirt bounced harmlessly off of a layer of defense magic.
"My disciple, do you remember when I warned that you would become some form of deformed monster? It seems that my wisdom is infallible, even now."
"Teacher, who kept trying to remove all of my limbs? I had to choose one or the other."
"Then why did you attach it onto another one of your limbs?"
"Ah."
Jane began seriously reflecting on his actions. Having realized the strangeness of his body, he manifested a small 'Force' rune inside his leg to break off the foreign bone. Then, he ripped out the tentacle-like limb and healed his wounds.
"It was good while it lasted, I guess."
"Well... this is the perfect opportunity for a belated lesson. My disciple, why do you think I only have four limbs?"
"Because you're a prick who's caught up on appearances?"
"And you're a monster who has already given up being human. No, it is simply more economical to only have four limbs."
As always, his teacher was so vague that Jane felt anyone else would have been unable to understand.
'Look at this guy, you might've killed me, but who's in control now?'
"You mean that it wastes valuable focus to use an extra limb, which would be better used somewhere else?"
"Precisely. Whatever you can do with an extra bit of flesh is nothing compared to what you can easily accomplish with mana."
"Huh."
---
"You..."
"What?"
"You take my words, filled with care for my disciple, and twist them like this...?"
"I took your words and applied them, Teacher."
Jane was standing shirtless in the forest, showing off his modifications. Holes on both sides of his abdomen were sucking air in for a second set of lungs, which worked in tandem with a second heart to pump blood. Indeed, Jane felt much stronger and energized than ever.
"I'm beginning to regret ever giving you that book on anatomy..."