best crossover fiction

Erza Scarlet, An S-Class mage of Fairy Tail who hold a seat at the Ten Wizard Saints and the Fairy Tail 7th Guild Master finally had ended her journey by offering her life to save her friends and those who she loves the most. Later that she learned that it isn't the end but yet a beginning of something new. The former who have lived her life as the queen of the fairies will now reign on the afterlife. Her journey begins here to become a shinigami and the queen of the dead- the scarlet reaper. I don't own the characters and anime just the story and the plot. It's just another Fan-fiction.

Translated Novel, I'm just a beginner translator, please guide me, senpai~ ... Kishi, a boy who dreams of becoming a powerful king, realizes he was born in the wrong world where such dreams are impossible. The world is unified under the eternal Dynasty, leaving no room for his ambitions. After discovering he can reincarnate, Kishi decides to sacrifice his current life and accumulate knowledge for 18 years to prepare for his next life. Upon reincarnation, he finds himself in a new, fantastical world where he is reborn as a prince, finally able to pursue his dream of becoming a ruler. ... (World: Shadow Garden, The Magic Revolution of the Reincarnated Princess and The Genius Daughter, The Contract Kiss, Fate, OVERLORD, Genshin Impact, Code Geass, and characters are too many to write down)

A story that follows three teenagers who meet various people and are faced with problems along the way.

Hello everyone, I was reading a few cross over comics that included Batman and Spiderman crossover to Captain America and Transformers crossover to fanfics that included Pokemon and Transformers crossovers. It looked like fun so I decided to write this while I am having a bit of writers block. BTW this will be like a short novel, less than 30 chapters. It will not be a full fledged book. If anyone wants to make these ideas full on books go ahead. Just give me a heads up because I would love to read them too. :D

Reincarnated into the body of Riser Phenex with the soul of an ancient phoenix in a world much like the world of DXD with a few twists.

Three years after Manhattan the Ray Sphere explodes in Empire City. Cole wakes up exhibiting strange powers, and he has to find a way to figure out how to survive when everybody suddenly wants his head. And then there is that guy with the claws too. Life suddenly got a lot more stressful.

Known as the Miss Perfect of business industry Elena Perez is living a 'perfect' life. Elena Perez is no other than the heiress of Perez Estate Company; the largest top company in the Asia. Blessed with Goddess-like beauty, excellent brain and wealthy background she is every man's desire and every women's inspiration. Being engaged to the well-known hottest lawyer worldwide; Luke Javier added a bonus on her seemingly perfect life. Meanwhile, a young woman who is completely unhappy with life May Gonzales is in an existential crisis after being dumped by her 34th boyfriend. She works as an office girl in the Perez Estate Company, lives in a rundown old apartment building, an orphan, sickly and often spends the rest of her day contemplating suicide. Two girls living a completely different life brought close together in an accident where their deepest hidden heartfelt desires were fulfilled.

Rose is an average teen girl in Japan who moves to a big mansion with tons of secrets awaiting her discovery. However, its not only secrets... there’s spirits. Both good and bad, and she gets to watch them either pass on peacefully to heaven.. or sucked into the darkness of hell.

5 sports prodigies with tragic experiences with their teams/mentors/friends bond over it online in an online organisation called "@ the prodigies." Together, they learn more about each others sports and struggles with their daily life. Developing a sense of brotherhood amongst them, they will do anything for their brothers. Will their teammates, friends, and families learn about their friendships with each other? And if so, what are they going to say?

​​Ky Kaito was born with an extraordinary gift. As a child, he was a math prodigy, seeing mathematics in every facet of life, including basketball. At an early age, Ky would watch basketball games with his father, revealing his incredible court vision. By the time Ky would step onto the court himself, he was a natural. Still, even with his skillset, Ky found himself on a losing high school team in the middle of bumfuck nowhere, failing to get college recruiters to notice him. After his last game as a high schooler, an agent offered Ky a deal. In exchange for testing out his new sports drink, Ky was given the opportunity to participate in Chronic Crossover, a reality TV show that takes inspiration from Korean elimination shows. What's the grand prize? Only a contract to the American Basketball Association. With something to prove and personal reasons for winning, Ky enters the competition, showcasing his sponsor's sports drink. However, Ky is surprised to find out that this sports drink does more than improve his performance, it gives him video game-esque abilities!