What Makes A Good Overlord Fanfiction Crossover Plot?

Sheeran, a 16-year-old boy, lived until he was killed for a stupid reason. ( stupid reason & more in the prologue:v ) But it seems that fate had stored different things for him as after death, His soul transmigrated to another world inside a dead body of a boy with the same name and same facial features as him. He also found out that a mysterious black whirlpool seemed to be inside him and connected to his soul. After the short unfortunate first life, he starts living his second life with more suffering that he chooses himself to get stronger but with that also comes happiness he had never experienced. A smooth sailing second life of Sheeran starts with something mystical inside his body and other benefits of it that could make him stronger with some suffering. However...he didn't know that due to his soul ( That was supposed to return to the source of the universe after death but instead, it transmigrated by someone for some purpose and that caused an adverse effect like increasing misfortune on his soul ) The benefits he receives ultimately becomes the source of his second doom that is even worse than death. But...that's when the future revoked overlord is born.

Evy was a simple-minded girl. If there's work she's there. Evy is a known workaholic. She works day and night, dedicating each of her waking hours to her jobs and making sure that she reaches the deadline. On the day of her birthday, her body gave up and she died alone from exhaustion. Upon receiving the chance of a new life, she was reincarnated as the daughter of the Duke of Polvaros and acquired the prose of living a comfortable life ahead of her. Only she doesn't want that. She wants to work. Even if it's being a maid, a hired killer, or an adventurer. She will do it. The only thing wrong with Evy is that she has no concept of reincarnation or being isekaid. In her head, she was kidnapped to a faraway land… stranded in a place far away from Japan. So she has to learn things as she goes with as little knowledge as anyone else. Having no sense of ever knowing that she was living in fantasy nor knowing the destruction that lies ahead in the future. Evy will do her best to live the life she wanted and surprise a couple of people on the way. Unbeknownst to her, all her actions will make a ripple. Whether they be for the better or worse.... Evy has no clue.

In a world where magic is a distant memory, where humans have the ability to harness a dormant power within them called Battle Force... A man from modern Earth suddenly awakens in the body of Norton Lorist, a young man of noble ancestry who has been exiled from his northern homeland by his family to Morante City, the capital of the Forde syndicate, under the guise of furthering his education. Little did he know what was in store for him when, years later, he received a summons from his family to return to the northern lands and inherit the position of head of the family... This is the story of his life before the summons... This is the story of his journey north and the allies he gathers along the way... This is the story of his rebuilding of his family's dominance and his protection against other power-hungry nobles... These are the "Tales of the Reincarnated Lord".

Azalias, an earthling transmigrated to an alternative universe, where humans don't exist. He transmigrated in time of an unique situation that he thought he was dreaming and had done a blunder. Which lead to our journey to be the Emperor of hundred Races.

After dying in prison from experimentation, I had gone back in time 2 years before my death. My faith in the Imperial Family, my affection for my own family, they can all go to hell! For that goal, I seek the second prince of this Empire, Azazel von Elysian for cooperation. "I will help you become the Emperor. In return, make me your Empress. I want everyone to be at my feet." With this agreement, we were bound by a bond where we would crush the Empire to create anew. I will make him the perfect Tyrant. - "Verena, tell me what you desire. I'll give it to you with all my heart." He whispered softly to my ear while holding me from behind, as if to lock me in his embrace forever. "Why are you asking me when we have already reached our goals?" He tighten his embrace, burying his head onto my shoulder. "... Please forget I asked." As time passes, he has developed a strong attachment to me, bordering on obsession. "Please don't abandon me... If you do, I'll kill myself." My eyes went wide, shiver ran down my spine as I unconsciously stepped back because of his threat. That Tyrant Emperor that I created is kneeling on the floor in front of me, the one who has used him. As if he's child who would be abandoned by his parents. I thought he would hate me at the least, but he turned into a crazy, obsessive tyrant that followed my wishes. He wouldn't let me escape his golden cage that he created for me. "If you're going to hell, Verena, bring me along with you." - Warning : The story contains adult content such as violence, consumption of heavy drinks, illegal drugs, blood and murder. Readers who are uncomfortable with the content, it's recommended not to read.

"What happens when you meet a tall and handsome elf king who has saved your life but kill your temper?" ~*~*~*~ "I'm more of a man in this house. Why can't you let me be on top?" Sean asked with a pout. Oswin groaned, rolling his eyes and wondering just how much more innocent Sean could be. "It takes a heavy responsibility to be the top," he replied. "Responsibility? Then it's perfect. I'm making more money, cooking,..." "Sean. I'm talking about things like stretching and penetrating," Oswin explained as he ignored the bulge in his pants. "Do you even have experience?” “Then teach me, your majesty.” “With pleasure.” ~*~*~*~ It all starts when the elf king, Oswin Alvingham, mysteriously gets stuck in the human realm and loses his powers. As he roams the unfamiliar一dirty and low class if he is to describe Earth, he stumbles into Sean Cooper, a fresh graduate, and a full-time table-waiter, who gets bullied in the alley. Though Oswin's magical power is lost, his physical strength remains invincible. When he rescues Sean, the latter decides to take him in as gratitude. And that is where the mess begins. How can the king of the elf cope with his new life? How can Sean convince himself not to be evil enough to kick his savor out of his house? Most importantly, how do an average mortal and the noble upper-class immortal live together under the same roof and on the same bed? ~*~*~*~* P.S: 1) This book contains mature and explicit 18+ scenes. 2) It also contains little graphic violence in some chapters, but I'll put a warning on the top of those chapters. 3) The ELF here is inspired by Lord of The Ring Series. Therefore, they are tall, slender and beautiful. Not tiny little beings like in children fairy tales.]