Oscar, with his access to the Abyss Prison granted by his master, fanned the flames of the furnace until they blazed out in roaring streams. Inside the forge room of the depths, the heat emanating from the furnace rippled across the layers of ash and soot, breaking their fragile gatherings apart into their baser specks. Oscar leaned his right shoulder, confused for a moment before realizing he once again tried to use his missing arm. His involuntary actions alarmed him. A useless movement could be his death sentence during battle.

'I'll need to hurry up and forge the arm, but can it be done?' Oscar slammed his hammer on the anvil to blow away the dust and reveal the fine steel underneath. He took out the last remaining piece of Diabond Ore, the spectacular diamonds within gleaming brightly from the flames, sparkling like the stars. Once the ore was placed inside the furnace, the flames barely glanced on its surface as if the ore rejected the flames. An elemental ore of higher grades required a fine amount of time for the temperatures to rise.

Resting on his chair, Oscar watched the ore slowly glow. A faint memory flickered in his mind, and he scratched his head, recalling what Gol-4 mentioned.

…….

Years ago, in Ashen Grove, he wiped the drool from his lips, gulping hungrily at the huge bird creature roasting above the firepit. Rain poured endlessly outside the cave, filling the air like an ocean, puddles pooling together to flood the entrance. Luckily, he carved out a moat and elevated his dwelling to avoid the hassle of getting wet. The nice fur around his body and the fires provided good warmth and comfort from the chilling air as he leaned against Erden in peaceful rest.

"In any case, the idea of creating replacement limbs for people was thrown out the window." Gol-4 finished his rambling, resting by the fire. He made a mechanical grunt and sighed, "What a terrible waste of potential. Grade Five elixirs are hard enough to make, and not everyone can have them. Imagine Exalts having artificial limbs. Some can create their own out of spells and Ein, but only temporarily. It makes my nonexistent heart dance to think of the possibilities."

"Let me guess, you want me to perfect it and find a way for them to be usable. With everything else you've put me to do, what makes you think I have the time?" Oscar tossed in several dry logs, and the fires crackled along the fibers, burning larger.

"My war may have gone far differently if all the injured Exalts had replacements for their unfortunate missing appendages. I'm sure you'll put the other designs to good work, but at the end of the day, the key factor is in the Exalts themselves." Gol-4's loud chattering tipped him over and rolled him into the flames. Oscar quickly retrieved him and stuck him on a pile of gravel.

"So, what was the problem?" Oscar asked, readjusting Gol-4 into the gravel to hold him in place.

"A bunch of problems. At first, I wanted to use an artificial core like a golem, which causes severe complications with the Exolsia core inside a person. The constant rejections between the two made me scrap that idea. Next, I tried to create an armament as a limb, but the formations inside clashed with the Exolsia. Then, I used the Exolsia core as the artificial limb's control function. The idea was good on paper, but nothing ever worked." Gol-4 spat out some gravel, tossing it along the small slope. "In my findings, I realized two things. One, the ore used needs to be an elemental ore corresponding to the elemental spark of the person. That is easy enough, but the latter stumped me."

"Oh? What was the latter?" Oscar asked.

"Stop interrupting me!" Gol-4 complained, making the mechanical sigh again. "Since the Exolsia would act as the artificial core and the formation for the limb to function, the question came to what material suited it. No known beast part was compatible with the person, so the limbs never worked. If I used the person's bones as the material, it could work, but the Fabricator and Alchemist Guilds frown upon such heretical means. But, even if I was allowed, the amount of bones needed to craft a good limb…might as kill the poor soul."

"Gol-4….you're a madman. What am I supposed to do about that?" Oscar tore off the bird's leg, around as large as a cow's flank, and tossed it to Erden to eat. He cut out his own and started to devour the succulent meat, oil dripping down his lips.

"Find a way. Maybe you could grow someone's bones." Gol-4 cackled.

"Sure. Might as well try for your sake." Oscar smiled.

…….

The Diabond Ore reached the critical heating point, a bright red glow all over its surface, obscuring the diamond sparkle. Oscar retrieved the hot ore and clenched tightly on his hammer, still not used to using his left arm. Like the tolls of a bell, the sounds of his hammer striking the ore rang across the forge, a fanfare of sparks flying around. The ore began transforming with each strike, blackened portions cascading off like rust off a sword. The many sessions of practice creating armaments for his soldiers paid off well. In a short time, the Diabond Ore had been processed to the highest degree of purity, far surpassing his previous work in Convecia City.

The refined ore was placed inside a large crucible to be used later. Oscar turned to Erden and lovingly rubbed the top of his friend's head. He spoke lowly, almost like a whisper, saddened by his selfish request, "I'm sorry, old friend. This might be the only way it can work."

"Say no more. We are bound, you and I. It's only natural I do this for you." Erden grunted and bared his teeth, groaning in exertion until a pained gasp escaped his clenched teeth. The antlers on his head protruded until they snapped off like a pair of twigs, followed by a heartwrenching cry from Erden, who breathed erratically but continued his agonizing self-torture. Oscar hugged Erden with one arm, feeling the body tensing from the pain, and he held tighter to reassure his companion. Whimpering, Erden released a tearful roar, and the antler wings on his back landed on the floor, thudding loudly.

"You believe my antlers will work?" Erden panted, nudging Oscar away, and plopped on the floor, uncaring of the soot painting his fur black.

"The Blood Transmutation between you and me made us share our physical qualities. Your antlers are pretty much like my own. If this doesn't work, then we wait for six years. Elder Saul's elixir will be done in that time." Oscar carefully carried the antlers as if they were precious children.

"Bastard. It'll take me time to regrow my antlers." Erden bobbed his head around, seemingly confused by the lack of antlers, the same way Oscar was with his arm.

Oscar heated the precious antlers of the Prielapos. The moment arrived, and Oscar grunted on each strike, pouring his emotions into his hammer. Gratitude, sadness, anger, and all sorts of emotions traced the veins of his heart. His own mistake cost him the arm, leading to this. He could not tolerate failure in producing a magnificent work. He owed it to Erden and Gol-4 to succeed. Oddly, the antlers provided zero resistance to his hammer strikes. Perhaps Erden's will lingering in the antlers allowed him to destroy it freely.

Once the antlers were ground into fine dust from his powerful hammer, they were gathered into a sack and slowly poured into the kiln, teal flames bursting from each handful thrown in. Erden breathed out his flames to keep the fires going. He emptied the rest of the sack into the kiln and waited patiently until the flames naturally lowered to below the kiln's opening, settling down. He found some good grade-three quenching oil, the Articus Oil, grateful to his faraway master, and doused the kiln, smoke pluming from the opening like a chimney.

Retrieving all the pellets of Erden's refined antlers, Oscar melted them down in the crucible, joining the beast material with the ore into a singular mixture. Now it came down to the Reis-forging. He could not allow his new arm to be lacking in its conduction of Reis. Slowly, he dripped the mixture onto the anvil, all held inside a mold. Layer after layer, bolt after bolt, failure after failure, and hour after hour, he persisted, reigniting the flames in the furnace for the tenth time.

"So complicated…." Oscar grumbled, bringing his hammer to the layered ingot as Erden helped him twist it slightly each time, coiling it to resemble the muscle fibers in a person. He measured out his arm and noted how long it needed to be, stretching the coiled product to match. The designs did not require an artificial formation but to be separated into many pieces. Looking at Gol-4's notes, he followed each instruction, pounding out individual plates and parts for the new arm.

Little metal stubs formed the fingers, the curved plates outlined the shape of the arms, and the round orbs acted as joints for the knuckles, wrist, and elbow. Each part was meticulously shaped and latched into each other easily, clicking into place. Oscar blew off the ash and soot off each part, wanting his new arm to be clean on the inside. The arm was nearly finished, and he performed the final process, heating it once more in the furnace and quenching it in the oil, the parts coming together into a single whole.

"Looks nice. Very nice." Erden praised, his appearance still odd to Oscar, who had grown used to the large antlers. Now, there was only a bed of white fur with small stubs where the antlers used to be. Erden growled, making Oscar chuckle. "Does it work?"

"Only one way to find out. I believe in Gol-4." Oscar brought the artificial arm to his shoulder, the hollowed-out space inside perfectly fitting his shoulder, all to the exact measurements. With a single click of a knob on the side, tiny needles stabbed into his skin, reaching his nerves, and he screamed out in pain, gripping his shoulder. The pain was far worse than he imagined. The needles acted as the entryway for his Exolsia core to exert its Ein and control over the intricate points inside the arm.

The Ein glowed blue under the teal plating, and Oscar felt a connection form between him and the artificial arm. Nervously, he sought to calm his lungs and tried to move his arm like he had always done. The artificial arm lifted up, invoking a surprised chuckle from Oscar. He brought the arm close to his face. The fingers moved accordingly, the wrist rolled to the perfect degrees, and the grip was stronger than his normal physical power.

"It worked!" Oscar swung his arm around, completely in control. Stomping his foot, he surged Eirin into it and threw out a Shattering Wave, its potency not lacking compared to his usual self. Lifting his arm high, he proclaimed to the heavens, "Hey, Gol-4! It worked!"