What are the possible themes suitable for 4th grade short stories?

A mysterious System led a mercenary, a love-stricken ghost, a deity seeking to regain power, all mounted on an Eastern dragon striving for survival, journeying through the myriads of worlds! The wheels of history, yet again they fucking moved forward! Rebirth, cultivation, alchemy, defying fate—you name it! Beautiful ladies, reverse harem, gods, monsters—not a single one missing! Everything is in "Top Grade Pure Beauty CEO"

Nine Tribulation Immortal Emperor, reborn in the city! One Earth, one Immortal Realm, the difference is as vast as that between heaven and earth!

The first year after the release of the game "Chaos". All the monsters within the game descended on the Blue Planet. The entire Blue Planet was reduced to an inferno. Dong Lei was reborn and came back to rewrite his destiny. He sold his family heritage and spent ten billion charging money in the game. In the game, he successfully got the SSS-level talent. Then he became a great emperor admired by millions!

[The Ultimate Feel-Good Novel] He was the Dark Supreme, the master of Ten Thousand Demons! Five years ago, he was trampled and humiliated like an ant, but today he has returned as a Demon, determined to let the world know the terror he can unleash! "Those who provoke me shall be killed! Those who obstruct me shall die!" — Chu Feng!

Su Jie transmigrated to a world of xianxia. He did not have a spirit root and his martial arts talent was average. However, he discovered that he possessed the Spirit Imprint talent. As long as he placed his spirit imprint, be it plant or animal, they would become his clones! When his clones trained, Su Jie himself would benefit. He could easily master a martial arts technique to completion or even the Immortal Martial Artist Plane that surpassed all limits! [Demon Ape Vajra Punch]: By cultivating the Demon Ape Body of Vajra, his body was impenetrable and his strength was unparalleled. He could topple mountains with his Body of Vajra! [Heavenly Silkworm]: The Heavenly Silkworm metamorphosed and broke out of its cocoon to become a butterfly. It transcended life and death, so it was undying and indestructible [Demonic Prana of Dragons and Elephants]: After awakening the Demonic Prana, a divine martial arts technique, his power would be boundless. The sky changed color at his command and he could crush both the heavens and the earth. Not only did Su Jie cultivate martial arts to an unprecedented plane, but even all his clones also became existences that were feared and adored by the world. Demon Ape King, Lord of the Bohai Sea, the World Tree…all of them were his clones. Su Jie declared, “You might still have a chance to survive if you defy the heavens. But you will never get a chance to live if you defy me.”

[Warning! #Yandere!] Aiden Cross was a boy who was smarter than a kid his age. Born on the seemingly normal planet Earth. Who finds his life very boring. 100 years ago, World War III happened for unknown reasons. Resulting in 25% of the world population perishing in this war and no one can talk about this due to the single organization which controls the world after the war. Does there lie a big secret behind the war that made all the previous nations fight for? Would he uncover the secret of the war? Or will he become a pawn of powerful organizations? But one day Aiden’s life turned upside down in an accident. Aiden lost his mother, and Aiden himself was on the verge of dying. Then he awakened the system and even met a beautiful yet haughty goddess. "You should feel honored you meet the great me hmph!" [Ding] [Compatible host detected] [Initializing the cosmic system] [Connecting the cosmic system to the host's soul] [Connection Completed] A system promises to make him stronger and help him revive his mother back to life. And inform him about the awakening of his world, which is no less than the apocalypse. With the help of the system, Aiden awakens Limit Grade Talent, but his talent is not complete and has a fatal side effect. [Talent: Celestial (unknown)] (incomplete) Aiden has to copy many talents to complete his talents. And travels to many different worlds. As he meets different races, a naive elven princess, prideful and lustful dragons, bored vampires, and a horny angel who offers herself to him  “I offer you my body and soul; please accept me." An angel with a flushed red face said  Unfortunately for our Aiden his big sis is a total yandere who couldn't even let him talk to another girl in front of her. Aiden has a dream of making a harem so he has to tread a careful line to get what he wants. Will he be able to have a harem or not? No one knows. But his otherworldly appearance wouldn't make it easier for him as he attracted many women's attention from a young age, which made his big sis even more jealous and crazy for him. Would he be able to have a harem in his long cultivation journey to revive his mother and discover many secrets of the cosmos with his yandere sister being present? Milfs, Virgins, Succubus, Vampires, Elves, Princesses, Demonesses, Angels, Goddesses, Dragons, Phoenixes, Dryads, Cultivation, System, Yandere, Otherworldly Handsome MC, and many more. _________________________ #No-NTR #No-Yuri #Yandere GOALS!!!! 200 power stones(weekly) = 1 extra chapters at the end of the week 50 golden tickets (weekly) = 2 extra chapters at the end of the week Donating Castle(or any other super gift) = 5 Chapters mass release(within 7 days) Join the Discord server at the link below to discuss the story. https://discord.gg/yD2GXRHHfp