The Ghost King's Wife is Sassy and Beautiful - Chapter 10

The world that nurtured the civilization which reached the pinnacle of magic was on the verge of destruction.
The last survivor transmigrated to the past, when the magic civilization started growing, as countless mages were still fumbling their ways through the thorny paths of magic knowledge.
He, who came from the end of the magic era, aim to reach the pinnacle of magic.

- Description from Novelupdates

Traveling to the world of Hokage, Kamiyo Colt witnessed the chaos of the Nine Tails firsthand.Without any special powers initially, he planned to develop quietly and survive until the Infinite Tsukuyomi. However, when he first trained his Chakra, his system finally activated.The system's rules were simple:By healing others, he could gain random attributes and skills.“Heal Uzumaki Naruto to receive pure Ashura Chakra!”“Heal Uchiha Shisui to gain his bloodline talent!”“Heal Sasuke Uchiha to obtain pure Indra Chakra!”In this way, Colt steadily developed his abilities over more than ten years.During the Fourth Ninja World War, when the ninja coalition saw him suddenly knock out the Six Paths Madara with a single punch, he looked innocently back at them.“What? I'm a medical ninja. Doesn't it make sense to defeat him with one punch?”

Our straight (?) bottom woke up ten years into the future and found himself on the bed of his childhood friend… At the start, the bottom was shocked to his very bones, but he soon quickly accepted this premise and found the whole situation to be rather amusing. Precisely then, the bottom once again went back to his timeline — back to when he and the top were just platonic childhood friends.

Landmines include but are not limited to: Sweet & naive bottom, a president story, logic is dead, slow-progressing romance, the protagonist’s name has too many character strokes, the names are hard to pronounce, too many gay characters…