Ankoku Kishi Monogatari ~Yuusha wo Taosu Tameni Maou ni Shoukansaremashita~ - Chapter 5: [Melancholy of A Goddess]

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.

Time back to 1981…

This year, the famous President Ronald Reagan officially took office as President of the United States…

This year, the world’s first personal computer officially appeared, and the era of Internet technology officially kicked off…

This year, the ten-year stock market crash has once again come to Hong Kong, the future Asian financial center, and an international metropolis alongside New York and London…

This year, the Cold War continued, the contest between the world’s two superpowers, the polar bear and the bald eagle, still has no winner, and peace is still far away…

This is the best and worst era…

It was also this year that he came…

- Description from novelbuddy

In Academy City, magic and science coexist in an unwavering power struggle. Toma Kamijo, an academically-challenged student in Academy City, wields the power of the Imagine Breaker in his right hand, which allows him to completely negate all supernatural powers – as well as his own luck. When he happens upon a mysterious nun named Index, whose mind has been implanted with the Index Librorum Prohibitorum – 103,000 ancient texts banned by the Church – Toma’s luck is about to be pushed to its limits when he finds himself in the middle of a war he never expected!