I was The Direct descendant of the Great Magus

200 years ago after defeating the Demon king the Great Magus leaves the human kingdom of Destian to explore and to Find a place where no one knows his identity and live a simple life and where his knowledge about every known magic will be past down to his future. Thats where he found a rural small village in the edge of the continent where he continued to live a normal found love got married and have two Children and found out that neither of them posse's any magic he was a little bit disappointed. With his spatial magic he created a space where he stored all of his knowledge in magic and named it the "Great Library" as the Coming of age of both of his sons, he told them that if any thier child posse's magic and at the coming of age they must give the key to the child that has an affinity with magic that can open the Great Library. The boys held on to the key their father gave them until the day of death soon they discovered that if they want to have an offspring that can possess that must marry someone with great affinity. The two set off to the capital to find someone to marry someone with, magic affinity since they came from a Remote village The two entered the kingdom's military as knights who later became high-ranking official knights but an unfortunate turn of events fell upon the elder brother and got sick so he entrusted the key to his younger brother who successful became a Noble due to his loyalty. The Magus Bloodline Continues to spread within a nobility Without them even knowing. 200 years later, the house of Windisor and the head of Household Duke Windisor finally a marry a mage as his third wife lady Elenore giving birth to a fully fledge mage named Nathan the second son of Duke Windisor. as the second son a the Duke didn't pay any attention to him think he just thier to extend the bloodline so he puts lady elenore and Nathan to a territory just right beside the main Capital as the duchess. lady Elenore was loved by the people rule with care and love every three weeks the Duke will visit them and immediately leave. 5 years have past Nathan is 5 years old and his older brother come of age has finally has come the House of Windisor continued to pioneered Thier swordsmanship through the years cultivating their knowledge and abandoning the Magic that thier great grandfather had mastered. on the birthday of his elder brother leonardo he will turn 15 which will be attended by a lot of noble family and of course the Royal family along with the first prince which hold the heros bloodline and the first princess who is the same age as Nathan. His elder brother leonardo is and the first duchess Theresa was a bit of a spoiled by the Duke so the second and third duchess doesn't get much of the Dukes glory since their just family extension lady Melissa the second duchess and lady elenore get along pretty much consider themselves as best friends and his elder sister Margaret is a very elegant lady and a future queen candidate and loves to spoil Nathan with sweets. they arrive on the party pretty early was greeted by everyone and was called by lady Melissa over to thier table which shared by the Duke family as well the Royal family The Duke and his first family stand out with thier red matching outfits with gold trimmings lady Theresa stands out like disco ball wearing a lot of jewelry from her neck to the finger while the two duchess just wear something simple yet elegant dress Margaret also attracts attention from everyone head turns wherever she goes wearing a simple blue green dress with her hair tied into a bun and has a pearl necklace that complement her silky black hair. meanwhile Nathan wears a white polo pair up with a black vest and tie and a simple black coat the last to arrive was the Royal family along with King Gregory Destian and Queen Sarah and with Prince Luke wearing his white uniform with gold trimmings and princess Liliana wearing a Royal blue dress with glitters and white gloves along with her tiara that matches her blonde hair well she very beautiful rivaling the queen lady Theresa and Margaret Nathan was mesmerized and was speechless for a moment princess then suddenly looks at Nathan direction and Nathan averting her gaze and continued to eat after the dinner the two duchess gave thier gifts and leaves the two duchess discuss the future of Thier child while waiting for the carriage lady elenore is a bit jealous to lady Melissa and lady Theresa and Their child has bright futures so she promises herself that he's gonna teach Nathan magic starting tomorrow to become a very talented mage in the future. Fast forward to three years and Nathan is 8 years old "mom it's been three years and you promised to teach me magic right" Said Nathan while pulling his mother "yes I know dear that's I called someone very close to me to teach you" that teacher was none other than his Father Sir Stephen Stewart the headmaster of the Magic Department at the Academy and former court magician when Nathan heard he got excited. The next day Sir Stephen arrives at the door and as soon as he opens the door Lady elenore runs towards to his father and hugged him after not seeing for 5 years "I miss you dad I super missed" the two hugged and other tightly "Oh geez you're already a mother and your acting like papa girl" Elenore then calls Nathan and introduce him "This is your grampa he has a special ability to see your potential in magic with his eyes" a person magic potential is measured by the color of the aura. Color red means the person is likely capable in offensive magic blue means Utility magic Yellow means support magic and also categorized by their capabilities. Daily nessescity magic is the basic magic involving a simple fireball Combat grade is composed of the basic enhancement spells along with basic support and attack spell military grade magic are considered to be deadliest including spells powerful enough to level a kingdom and is top secret and the last is the Magus grade which is the highest and only the Great Magus can perform. when sir Stephen look at Nathan he saw a white aura which means he can master every known magic and is considered to be rare kind of Mage "Well my grandson I can see that you will be the future of magic in this kingdom" Nathan eyes widens from excitement Lady elenore told him to wait for his grampa at the garden "Dad what did you see in Nathan" Sir Stephen sigh "he has a rare kind of aura just like the one 200 years ago" in the history of magic the only one with the white aura was the Magus thus he was able to master everything and perfected it to it's full potential. At garden the the two started the lesson "So my dear grandson my question is what is magic?" Nathan tilts and scratches his head "I don't know super powers to kill bad guys" Sir Stephen demonstrate by making a flame appear in hand "This is gift from the gods given to us so that we can defend ourselves this was not given to us to kill or hurt other remember that" Nathan nods with amusement "To draw out the mana you feel it first and once you feel it concentrate and visualize the spell" Nathan concentrate and visualize the flame he saw earlier and was able create a big ball of flame he amazed for a moment but the flame got bigger and bigger Nathan got scared and unleash a full power fireball Hitting one of the garden wall and destroying it alerting everyone in the mansion Elenore rushed towards the garden seeing nathan blows up a Hole in thier garden. Elenore was worried at first but seeing her son Happy is already enough for her the grandson and grandfather duo continued to practice until noon when it's time to leave "remember what I taught you and you will achieve greater heights" The next day they practiced Physical enhancement and healing which he also picked up quick the following days his Grandfather brought some more books and materials which Nathan all studied. he learned everything that his grandfather taught him. a year have passed since he learned everything about magic but Nathan feels like he was still far from his full potential so he kept on practicing even without his grampa's guidance. On his tenth birthday which was only celebrate by his maids butler and cooks along with lady Melissa and his older sister Margaret. "Two more years and you'll be entering an academy what will you be joining" ask Margaret Nathan replied "Grandpa said I'll going at his academy" Margaret was surprised to learn that Nathan was a mage instead of a swordsman "I thought you'll be learning swordsman since it runs from the family" said Margaret "I don't know it's like my body's isn't made for swords" said Nathan they continued to talk until it was time to leave. lady Melissa and Margaret left pretty to attend the Royal family dinner and the arrangement of lady Margaret and prince Luke engagement he was expecting his father to arrive but he didn't instead was given was a key that been in the family care for more than 200 years and now he has the key that will changed everything it arrived In a small box with small piece of paper wrapping around it on was the paper was the instructions to open the Great Library. He opens it and sees the key wrap in a paper he then removes the paper gently and sees instructions or movement to activating the key he then proceeds to follow the instructions while holding the key he then performs a vertical line going from above his head to his front and twist the key like he is opening a lock and then a doors appears all of a sudden from out of nowhere the Door had an Oval shape with magic circle serving as lock to the door because it's already open he pushed the door out and revealing a massive library of Grimoire and tome from ancient magic and many more. the space was massive it seems endless at the center there was a tome that attracted Nathan he head towards to the book and opens it the crystal above the book suddenly flash and a image of a person appears "If you managed to open the door it mean my legacy will continue as the Great Magus I must pass on the knowledge I've been learning to you will be the future that will shape the world you know but if Opened after many centuries there is still hope I wish you good luck my descendant" after the message he was shocked to learn about his family secrets not even the Duke knows But it doesn't matter he will now be the one that will change the course of action by understanding the very roots of magic