In LOTR with Harry Potter system - Chapter 379: The Conference Begins

A genius talisman practitioner is reborn as a seven-year-old girl! However, her innocent appearance belies her vicious personality.
In the remote countryside, the Crown Prince runs into her, beating up her enemy. She is indifferent, but it’s love at first sight for the Crown Prince!

“Not good, Your Highness the Crown Prince, Her Highness the Crown Prince Consort used an immobilization talisman on His Majesty the Emperor, and His Majesty is currently eating dirt in the main hall.”

“Isn’t that normal? Who told that dog emperor to provoke my wife? I say it’s a job well done! Pour a bucket of ice water on him to cool him down!”

- Description from Novelupdates

After the nuclear warfare, massacres started to spread throughout the entire world. The order between humans completely collapses, and the strong eats while the weak gets eaten becomes the #1 rule.

Betrayed and left for dead, Richard Blackwood—formerly known as the world renowned hero Astralis—awakens a decade later to find the world has moved on, and an imposter now wears his mantle. Disguised as a rookie in the Mage Guild, he quietly hunts for answers.'If my little sister is levelled above me, then what about everyone else? How much stronger have the bastards who betrayed me grown while I was dead?'Richard must grow stronger once again, and rise much higher than the S-Rank.'What the fuck? I almost die, and I get a power up?'Not harem.

Chen Yan travels between worlds, ending up becoming an honorable prince in a medieval fantasy world. Yet this world was not quite as simple as he thought. Witches with magical powers abound, and fearsome wars between churches and kingdoms rage throughout the land.

Roland, a prince regarded as hopeless by his own father and assigned to the worst fief, spends his time developing a poor and backward town into a strong and modern city, while fighting against his siblings for the throne and absolute control over the kingdom. Join Roland as he befriends and allies with witches and, through fighting and even farming, pushes back invaders coming from the realm of evil.

- Description from Novelupdates