Caster of Black

One of the Servants of the “Black” camp. His true name is Avicebron, but his official name is Solomon ben Judah ibn Gabirol. He was a philosopher, poet and Kabbalist, a magus who used the magecraft branch of Kabbalah, from the 11th century. He also has the nickname of “Plato of Judea.”
It doesn't need to be said, but he's completely unrelated to Solomon, the son of David who was served by 72 demons. Fearing that their names might get mixed up, I decided to use “Avicebron” instead.
As a Caster-class Servant, he is the type that's a bit hard to handle. He is basically loyal to his Master, but great expense and time is needed in order for him to display his full abilities. Darnic had Roche summon Caster first because a large amount of time and a budget great enough to bankrupt a regular magus ten times over was needed just to construct his workshop for making golems. However, once he gets on track, he can create golems for making more golems, so perhaps not being too concerned about labor cost is a virtue for him.
He was weak and feeble due to suffering from many illnesses, and his skin disease was especially serious. As a result, it is said that he was pessimistic and gloomy, and in the novels he fully displays that personality. After all, even when he died, he kept wearing his mask and never revealed his face.
According to history, Avicebron is said to have imparted his philosophical ideas from Arabia to Europe. Also, he created the word “Kabbalah” from the Hebrew word for “receiving.”
According to legend, he made a female-type golem to take care of his daily household chores and necessities. In these novels, he tried to create the “first human Adam,” similar to Victor Frankenstein. However, unlike Victor, who simply acted out of ambition, Avicebron's goal was to sweep away the suffering of his people and attain true Eden.
His personality is timid and cool-headed. While he understands his own weakness, his ardor in participating in the Holy Grail War was unusually great. However, his objective was mostly granted by creating and activating “Adam.” How “Adam” would act after that was something unrelated to him.
Even if he was destroyed, Avicebron would merely accept that result.
The reason he joined sides with the “Red” camp is, rather than for the sake of self-protection, because his objective wouldn't be achieved if he remained with the “Black” camp, so he chose the better choice.
The reason he was pierced by Archer of “Black”'s arrow with practically no resistance is partly due to his weak physical strength, but also he had already resolved himself to become nourishment for “Adam.” Fighting alongside a Master who respected him didn't feel bad to him at all, but even so, he couldn't defy the temptation of to have his wish, which he had devoted his entire life to, finally within reach. And he simply thought that he should pay reparations for that choice. For Avicebron, his own life was worthless in his eyes. To put it more accurately, the moment his Noble Phantasm was completed, he logically concluded that his value had become zero.
According to legend, he was killed by a man jealous of his poetic talent and was buried beneath the roots of a fig tree. It is said that the nearby people who thought it was strange that the fig tree was producing such overly sweet fruit dig it up, thereby exposing the man's crime—

Fate/Apocrypha material: Fate/Apocrypha Encylopedia