What could be the plot in a Naruto and Seraph of the End crossover fanfiction?

The age of darkness has arrived. When the rift to an unknown plane suddenly appeared on Earth, monsters invaded, beasts mutated while humans, the once-dominant species fell to the bottom of the food chain. A hundred years later, three of the greatest classes evolve amongst humans: ability users, ancient warriors, and gunslingers. Qin Feng, an orphan of this dark age was tormented just as he awakened his pinnacle level of special ability, barely surviving for ten years in the post-apocalyptic world. Hence, he was reborn...

When Yu Yao opens her eyes, she realizes that she has transmigrated into a book that she had once read. It's a book containing a typical story about a real daughter and a fake daughter. The real daughter was framed, and the fake daughter was pampered by everyone. Her biological brothers had only been doting on her fake younger sister—who had been switched at birth—and hated Yu Yao tremendously. They even believed her fake sister's lies and sent Yu Yao to a mental hospital. Yu Yao is in the mental hospital being tortured by a perverted director when the story begins… Our protagonist has transmigrated into the body of the pitiful real daughter, Yu Yao. She is racked with helplessness at having to endure this living hell... What bothers her the most was that this was only the beginning. She's aware that even if she escapes the hospital, her fake two-faced sister would not let her off so easily. Her elder brothers, who do not recognize her as family, would also help this deceptive snake in dealing with her. In the future, there would be constant trouble, and living a peaceful life would be far out of her reach. Just as she perks up and prepare for battle, there seems to be a shift in plot... The Second Brother, who had always been the meanest to her, rescues her from the mental hospital hastily and starts showing her concern. He is tender and affection is written in his eyes. Meanwhile, her most ruthless Eldest Brother, who had never considered her to be his younger sister, starts treasure her. He begins listening to her every demand whilst cold-shouldering her two-faced fake sister. Yu Yao is confused. What's going on here? This isn't in the script! Why was she, who was supposed to be shunned by all and constantly the target of their bullying, suddenly being pampered by so many people?! It was only after a long time that Yu Yao realizes what had happened—her elder brothers are all transmigrators too! Originally, the book ends with a tragedy befalling the family. The two-faced fake sister betrayed them all and sent them to a tragic end. It was Yu Yao who rescued them and died in the process. After Yu Yao's elder brothers transmigrated, they swore to protect Yu Yao with all their might as they worked endlessly to win her favor.

Reborn on an ordinary Shionin of the Uchiha clan, Ryu thought he was going to spend a life of inaction, but he did not expect to bind the sign-in system. Check in at Kannabi Bridge and get reward [Rinnegan ] Check in at Hokage Residence and get reward [Flying Thunder God Jutsu ] Check in at Valley of the End , Get reward [Sage Body ]

When I died I didn't expect to wake up with dark beings of immeasurable power looming over me. I didn't expect to be given new life in a brand new world. Now, armed with a powerful system that makes me stronger after every fight, I might be the last thing standing between the multiverse and absolute annihilation. As I complete quests, defeat foes and become stronger, I still don't know if I'll be able to save this world, my old world and all the worlds in between. "And below... the MAW beckoned..." Come check out the discord to speak to the author and other readers: https://discord.gg/BEJgcRVVev

"What kind of guardian would you want to be? the one who destroys everything or the one who protects everything?" Jason, one of the many casualties during a nuclear explosion gets the chance to reincarnate into another world due to his deeds during the war. He gets tossed to another world due to ending up with the Shadow god as his patron, something deemed impossible. With a system to guide him in the world of Clover and a family jinxed through the generations, his adventurous life in new world begin. --- Note: This novel is slow-paced till the 50s. It picks up pace after that. WC per chapter: 1600~2200 words Includes a few chaps with 1100~1300 words I don't own the cover

Ryu Otsutsuki always wanted an easy life. He... Was not destined for it the moment he was born into this world. Given incredible power, the third son of Kaguya Otsutsuki had to deal with his brothers, and immortality. And now... He promised his brother he'd help him with something... Which was... Troublesome... I hate you Brother! OP OC/Sharingan/Mokuton/Rinnegan/ (COMPLETED)