Koshi does not truly possess a personality. Also, he is incapable of having emotion. Due to Hiro's life being impreinted on his mind, he has many of his mannerisms. He is honorable, loyal, valiant, and coruageous. Being an automaton, he cabbal feel emotions, though he can simulate them particularly well.
Koshi's appearance is that of his creator Hiro in his phsyical prime. He appears to be an 18 year old. Japanese male. He is tall, 6'3, and has a slim muscular build, long black hair, and piercing gray eyes. He also has a flaming hammer tattoo on his right arm.
Hiro Roshida had always been a favored son of Hephaestus. Since his return to Kyoto from Camp Half-Blood in 1992, Hiro had been famed for his brilliant inventions as well as his strides in Mechanical and Electrical Engineering. He's had luck on his side, being married to his long time girlfriend and daughter of Tyche, Eliza Roshida.With Hiro's inventions, the Roshidas made billions, and with this wealth, Hiro built a home in Tokyo, filling it with the most cutting edge technology, a majority of which was of his own design. Along with it, he also created an artificial forge that used a nuclear reactor to create heat, equipped with a supply of clestial bronze he'd taken from camp. And for years, he created. Eventually, Eliza died of Lukeimia. Not too long after, Hiro's health had also began to fade as he had contracted Lukiemia as well. He realized too late that the radiation from his forge was killing him. It was then that he created Koshi. Now closing in on his 40's, Hiro desired to regain his youth. His plan was to complete his new body and transfer his soul into it. He'd seen it done before, and figured it would be simple enough. He created his own likeness at the time of his prime. He was 18, young, strong, still promising, and with his knowledge of the present as well as his acquired wisdom and experience. This new life would be perfect. He created a new mind for himself. A mind that wouldn't fade like his had begun to. A powerful supercomputer. He copied his mind as a whole, his thoughts, ideas, experiences, memories, into this computer and implanted it into his new form. He created flesh from the celestial bronze, combining it with severalspecially made plastics and rubbers. Soon, the preparations were complete. He would finally be immortalized in celestial bronze.He was preapred to ascend to immortality, and as such wasn't prepared.Telekhines stormed his home and nearly destroyed everything. Caught off guard, Hiro was left dying on the floor, and he prayed to his father, who took piy on him and appeared to him. Hephaestus looked upon his son sadly, and offered to transcend his soul into the automaton for him. Tearing up as he lay there dying, he refused, saying he was a fool to want this. Only a god can be immortal. And with that he died. Hephaestus, sad for the loss of his son, looked upon the automaton. He took it with him to a workshop of his in the Ridge-and-Valley Appalachians. There he created a perpetual motion/Greek fire energy cell and implanted it into the machine, giving it a "heart", bringing Koshi to life. Upon coming to life, Koshi belived himself to be Hiro, as he had all of his memeories up until before the attack. Koshi served as an assistant to Hephaestus in his forge for 2 years until he finally sent him off to Camp Half-Blood, telling him that he would be a better fit there, and that even being a machine, he'd be better than most of the demigods there. Though when Koshi left, The Smith god turned to him and said, "Goodbye, Hiro..."
Koshi traveled the mountains for 3 days before finding camp. He goes to Alexander the Great, and asked him if he could be allowed to stay at camp. He agreed, and now Koshi resides in Bunker 9, as he enjoys working in the forges.
Despite Koshi being of a more technologically advanced design, his weapons are much more steampunk inspired, as he enjoys the irony
Koshi's right arm can transform into a cannon that fires exploding celestial bronze cannonballs
He has a Staff that can shoot Greek Fire
Celestial Bronze Sword