MTL - I, The System Maker! - Chapter 47

(Naruto + Single Heroine Tsunade + Romance + Action)A failed author transmigrates into the Naruto world, becoming the younger brother of Konoha’s White Fang, Sakumo Hatake, and the uncle of Kakashi. He gains a cheat ability—enhanced cellular activity.Coincidentally, just before the Second Shinobi War, he participates in a Jonin meeting where he supports Tsunade's proposal ahead of Dan Kato, marking his first encounter with her.From then on, he launches an intense pursuit, winning her heart during the war.Tsunade: “Kawakaze, why do I keep losing to you?”Kawakaze Hatake: “Because I’d like to live a few more years...”Kakashi: “My uncle is amazing, I’m his biggest fan!”Kawakaze Hatake: “Keep it low-key, keep it low-key.”

Once she crossed through, she actually became the disfavored third WangFei?

Ning Yechen used to be the Demon Lord. He singlehandedly took over the Demon Realm and attacked the Heavenly Realm. His name preceded him throughout the Six Realms. He got tired of fighting, so he quietly went into seclusion and became a happy hermit.One night, an Empress from the Heavenly Realm fell into the Mortal Realm after someone drugged her with an aphrodisiac. She inadvertently fell into his room, and they made out. After the deed, the Empress quietly left. Just when he thought he would never see her again, she showed up in front of him ten years later, bringing a child, saying it was his daughter and demanding accountability from him! “She’s your daughter. You have to be responsible for us!” Ning Yechen was stunned!

Waking up, I discovered that I had become a cat with superpowers...