Two authors find themselves in an Overlord fanfic (A Vulpine Spanner in the Works) as Nameless Archer (Emiya) and Tamamo-no-Mae from Fate Extra. Shenanigans Ensue.

Orario, the city of adventurers' paradise. Everyone who comes there has their own ambitions. Some want to become strong, some dream of restoring the pride of their race, and others aspire to become rich and famous. Among them are those who can be considered naive or foolish-those who wish to become Heroes. Of course, Emiya Shirou is one of the foolish ones.

Emiya Shirou knows one thing. This was screaming Zelretch all over his new arrival in this unfamiliar world one where many horrible things happened as he and a band of psychopathic idiots had to solve it. Archer!EMIYA x Limbus Company

After his contract with Alaya is over, Shirou Emiya, aka Archer, is sent into the cycle of reincarnation after being told that his beloved Artoria Pendragon did the same while waiting for him. He is reborn into a new world due to a very powerful being taking him away from his world and planting him in its homeworld. Archer is then reborn as the son of the most unexpected woman in the entire multiverse: Artemis the goddess of the Hunt and Moon. He is named Perseus by his mother and left on the doorstep of a dear mortal friend of Artemis's as his biological father died in a car crash the night of Percy's birth. When Percy turns 16, after the Titan War, he is found by the satyr Grover Underwood and is claimed during his first game of Capture the Flag. What happens next? Well, only Chaos knows.

shirou emiya merges with hephaestus the god of forge after being absorbed by the grail, he will try to help the heroes of old to get happy endings.

Shiba Ryuji The Infamous Hitokiri battousai in the Modern hero society and also known as the Swords man who killed one thousand villains. His Ideals is the Cleansing of the world through blood and force during his dark days as an assassin. Using the Style he Mastered from his childhood, Hiten Mitsurugi Ryu which Is the Flying heaven swordsmanship which he was taught to fight off the villains and also the ursurpers of the dark Era. As of Contrary of Izuku Midoriya whose ideals to Save people with a a smile, Shiba saves people with a Sword and sacrifice by blood. (A/N I AM SO SORRY TO REMAKE THIS! BECAUSE I HAD BETTER IDEAS FOR THE BOOK ALL THE WAY BACK TO THE EPISODE ONE!)