Transmigrate into Saber: From the Start, I Slay My Master with One Strike

[Transmigration + System + Invincible protagonist + Feel-good story + Subverting expectations + Lighthearted + Anime crossover + Self-discipline + Saber + Type-Moon] Wuda University’s fencing champion Lin Qiu accidentally transmigrates during a match and becomes Saber! His Master tries to take advantage of him from the start? He swiftly cuts him down and teaches him a lesson! He doesn’t need a Master. He can fight on his own, and self-discipline gives him an infinite mana supply. He defeats Lancer, recruits Rider, saves Sakura, and takes on Rin. The rules of the Holy Grail War? I am the rules! He cuts his way to victory and turns Type-Moon upside down. His invincible journey of self-discipline begins!