I've Already Confronted the Five Kage, and the System Just Arrived! - Chapter 110 -

Rowan was just a broke college dropout—until he was summoned to another world.Dragged into the war-torn realm of Laronia, Rowan stands beside four other chosen heroes, each blessed by prophecy… except him.While the others awaken to legendary powers and divine roles, Rowan receives a blank grimoire. No magic. No title. No future.Cast aside and marked a failure, he prepares for death—until the silence inside his grimoire begins to speak.The gods made a mistake. And this world is not ready for what lies beneath the Wordless Mage.

Kanda Kyoichi transmigrated to Konoha and became a temporary instructor at the Ninja Academy. Fortunately, he awakened the Mentor System.By teaching others, he could earn rewards.Thus began Kyoichi’s career as a “teacher” in the ninja world.Shisui: “Sensei’s unique interpretation of the Will of Fire has given the Uchiha Clan a true sense of direction!”Asuma: “The essence of the jade lies in protecting the people, with the advanced leading the way for the less experienced. Only then can Konoha become stronger!”Kakashi: “He’s my life mentor. He transformed Konoha!”...Years later, in the memoirs of Kyoichi, now the Hokage, he wrote:“I honestly just wanted to be a life mentor!”

A man is reborn into the world of Avatar: The Last Air Bender as a waterbender from Katara's tribe. Best of all, he was the same age as her, and he had a system with him to help.He knows the future and a system that lets him continuously get stronger by completing quests or long-term missions, as well as giving him the ability to copy abilities from others for himself. He will become invincible in the world of Avatar, even more so than the Avatar himself.

This is a story of an ordinary boy gaining unusual powers from his nightmares… It all started when Lin Sheng experienced something strange on what he thought was just another normal day. He begins to have recurring dreams that lead him on an incredible journey of discovery as he encounters spine-chilling monsters and elusive secrets.

- Description from Novelupdates