Extra of luminous academy

After dying, the main character finds himself reincarnated as an extra character from an unfinished series of novels he was reading. The new world is a fantasy setting where students attend the prestigious Luminous Academy to learn magic by contracting with spirit swords. In this world, swords are divided into three ranks: mortal, elemental, and the highest immortal rank. While the original protagonist is a master of an immortal rank sword, the reincarnated protagonist has only acquired a low-rank mortal sword.