Sebastian Aurelius Castellanos stood in the dimly lit study of his family's ancient mansion, surrounded by shelves of books and aged artifacts. The scent of parchment and old wood filled the air, and the only sound came from the gentle ticking of the large grandfather clock in the corner. As he gripped the broken sword, his catalyst, his thoughts were consumed by the upcoming Holy Grail War and the unknowns that lay ahead. He felt a mixture of anxiety and anticipation, but he was determined to give his all in this battle.
The door to the study opened, and a man with silver hair and a regal aura entered, flanked by a pair of familiars in the shape of winged lions. Sebastian recognized him immediately as Lysander Euryale, the mediator for the Holy Grail War.
With a nod of acknowledgement, Sebastian welcomed him into the room.
"Good evening, Mr. Castellanos," Lysander greeted him, his voice as smooth as silk. "I trust you are prepared for the summoning?"
"I am, but I must admit I'm nervous," Sebastian confessed, his voice wavering slightly, idle fingers fidgeting with the cufflinks of his suit. "I have no idea who or what I might summon with this catalyst."
Lysander's expression softened, and he offered a reassuring smile. "Such is the nature of the Holy Grail War. In my opinion, it's the unpredictability that makes it so intriguing. The broken sword you hold surely symbolizes a fallen warrior of great might and skill, and yet, the only Servant Container left is an Assassin. One can only wonder whom you might summon, who is both a mighty warrior, and yet, a harbinger of hidden death. Whatever the case, trust in yourself, and the catalyst, and an awesome force shall surely manifest in response to your call."
Sebastian nodded, taking a deep breath to steady himself. "You're right. I must trust in my abilities and the bond I will form with my Servant. I'm ready to begin."
Sebastian Aurelius Castellanos solemnly headed down to the vast ritual room of his family's mansion, the faint scent of aged wood and magic lingering in the air. The dim glow of candles illuminated the intricate circle he had carefully drawn on the floor. Twelve cats, his loyal companions, watched the scene with curious eyes. Lysander, the overseer of the Holy Grail War, loomed in a shadowy corner, even now guiding him through the process of summoning his Servant.
As Sebastian prepared the ritual, Lysander observed, his eyes filled with a sense of duty. "Remember, young Master, the catalyst you have chosen will determine the Heroic Spirit that shall be your shield in this War."
Sebastian nodded, clutching the broken sword hilt in his hand. "I understand. I hope this warrior, whoever they may be, will find it within themselves to fight by my side."
With a deep breath, he began to recite the ancient incantation, his voice echoing through the chamber. The room trembled with power, and the air crackled with magical energy as the circle came to life. The cats scurried away to safer corners, their tails puffed with anxiety.
As the summoning reached its climax, a figure materialized within the circle, shrouded in shadows. The air was heavy with an ancient presence, and the figure stepped forth, revealing the imposing form of an Assassin-class Servant. Clad in a dark cloak and armor, the Servant's eyes gleamed with wisdom and authority. In his hand, he wielded a formidable sword, despite the Hassan's typical preference for daggers and other such easily concealable weapons of their trade.
"I am the Old Man of the Mountain, Hassan-i Sabbah, summoned to answer thy call. By thou command, thineself shalt be as thy eft sword in ye Holy Grail War," the Assassin spoke in a solemn, old-timey manner that echoed through the room.
Sebastian stared in awe at the legendary figure before him, the voice of his Servant carrying an ancient weight that rattled him to his very core, full of timeless wisdom and ancient power. Sebastian struggled to find his voice. "I-I am honored, Old Man of the Mountain. My name is Sebastian Aurelius Castellanos, and I shall serve as your Master."
Hassan-i Sabbah bowed his head in acknowledgment. "Hmmmm, by providence's divine grace, t'would seem thine meeting and compact was preordained by causality itself. Thyself glimpses naught from thou in the way of selfish vainglory, nor the arrogance to impose thy will upon The Lord's endless designs. Thy lord's righteous hand of grim retribution approves of thee, and acknowledges ye as thy Master till the Grail War's conclusion. Together, we shall stand as judicious testament to the glory of righteousness. Quicken now, that we might fly fain to yonder gast battle, young Master."
"That sounds good to me, Assassin. Though, and I mean no offence, but I think we'll need to work on your vocabulary in the meanwhile."
"Mayhaps..."
As the two prepared to face the trials of the Holy Grail War, already, a nigh unbreakable bond began to form between the Master and his ancient Servant...
Sebastian and Hassan-i Sabbah spent the days leading up to the Holy Grail War getting to know one another. Despite the legendary Assassin's imposing appearance and archaic manner of speaking, the two found common ground in their shared sense of honor and determination to protect what they held dear.
Sebastian often found Hassan-i Sabbah in the mansion's library, poring over ancient texts to better understand the modern world. The Assassin's dedication to knowledge fascinated Sebastian, and he was eager to learn more about his enigmatic Servant.
As they sat together in the library, Sebastian asked, "Excuse me, vaunted Old Man of the Mountain, may I inquire what brought you to the path of an Assassin?"
The ancient Servant paused, his gaze lingering on the worn pages of a book. "I once led the original Order of Assassins, the Hashashins, in the distant past, young Master. I sought to uphold justice and purge the world of those who threatened the balance. However, I realized the path of a man-reaper ordained by providence to render murderous judgement was not merely one of mindless violence, but also of wisdom and understanding."
Sebastian nodded thoughtfully. "I see. I have always believed that knowledge and compassion are the keys to overcoming adversity. My Element and Origin, Shield, have guided me to protect and defend those in need."
Hassan-i Sabbah looked at his Master, his eyes filled with respect. "Thou art a wise and noble soul, Sebastian. I am honored to stand by thy side as thy sword in this War."
In the days that followed, the bond between Master and Servant grew stronger. Sebastian introduced Hassan-i Sabbah to his family and his twelve cats, and the ancient Assassin, to Sebastian's surprise, showed a gentle touch with the feline companions. They shared their knowledge and strategies, preparing for the upcoming battles.
As the Holy Grail War drew closer, Sebastian and Hassan-i Sabbah stood together, united by their shared sense of honor and duty. They knew that the challenges ahead would be great, but their unwavering bond would be their greatest strength in the trials to come.
The eve of the Holy Grail War had arrived, and Sebastian, clad in his black suit, stood with Hassan-i Sabbah in the courtyard of his family's mansion. The moon cast its pale light upon them, as if blessing their union before the battles to come.
"Hassan-i Sabbah, are you prepared for the trials that lie ahead?" asked Sebastian, his voice filled with determination.
The ancient Assassin bowed his head solemnly. "Verily, my Master. Thou hast my unwavering loyalty, and together we shall vanquish our foes and emerge victorious."
With a nod, Sebastian led Hassan-i Sabbah out of the courtyard and towards the pre-battle meeting grounds. As they walked, the air grew tense with anticipation, the weight of the impending conflict bearing down upon them.
Addendum: Character Profile
Master: Sebastian Aurelius Castellanos
Appearance: A 170 cm tall young man of European heritage with fiery red hair reaching down above his shoulders and imposing blue eyes like water that hides his gentle nature. He mainly dresses in a black suit but when going casual he can be seen wearing a dress shirt and black pants. He has an average body build for a 20 years old man but he is neither too broad or too thin, yet still showing a bit of muscle despite his merely passing physicality.
His command spells take the shape of a turtle. With each spell the turtle retreats in its shell starting with the limbs, then the head, and finally its shell.
Personality: Despite what his eyes may show you, he is in fact a calm and gentle person. He is charismatic and intelligent, always looking for opportunities. He detests evil and their actions and would never work along with them unless left with no choice. He abolishes the waste of human life and thinks that each human is destined to do great things. One man, two man, everyone can change the path walked by humanity.
Background: Sebastian comes from a rich but unremarkable Magus family whose members are his father, mother, younger sister and himself. They live in an old mansion constructed by them that is maintained by their workers, maids and butlers. His father and mother are both Magus whose elements are water, an inconvenience considering his differing element, which has left most of their Magecraft hard to use for Sebastian. Due to this he has had to adapt and overcome his limitations. He had the habit of adopting cats ever since he was young, either from shelters or the streets. At this moment he has twelve cats, each named after the months of the year, from January to December. They are pretty smart, though not quite as much as the familiars one may find from a normal Magus.
Element and Origin: Shield
Abilities: Sebastian possesses an above average number of magic circuits, despite all his family members possessing the Element of Water, Sebastian had the unusual circumstance of both his Origin and Element being designated as Shield. Due to his Origin and Element being far removed from the table of the Five Elements Sebastian has a hard time doing things such as creating fire. He is proficient in reinforcement magic though nowhere near a master, he mostly uses it to enhance his heart which helps to strengthen his magic.
Magecraft: He specializes in barriers and bounded fields, seeing them as easier to do for someone like him who has the Element of Shield, he can extend a line that creates silver shield as big as he can make it that he can move around as he pleases. He learned creative ways of using his Magecraft such as platforms or imprisonment, with enough time and resources he can add effects such as a bounded field where wounds cannot heal but neither damage can be inflicted.
Wish: Despite being chosen as a participant in the Holy Grail War Sebastian does not possess a wish, though if it means that someone else other than him could have their wish come true he will put his body to the test to complete this ordeal.
Catalyst: When deciding for a catalyst he decided to use a broken sword that had been split in half, leaving in his hand the hilt, along with what was left of its blade.