Rudeus Greyrat.

Father Paul Greyrat. At first, Rudeus didn't see him as a father figure, but as a close friend with similar interests. Their relationship is marked by conflicts and reconciliations, and Paul's death deeply affects Rudeus.
Zenith Greyrat's mother. She sees her son as a genius and actively supports his development.
Sisters Norn and Aisha. Their relationship with Rudeus is complicated: Norn initially feared and hated her brother, while Aisha, on the contrary, immediately accepted him.
Mentors. The talented sorceress Roxy Migurdia became his first mentor, and he later trained the noble heiress Eris Boreas Greyrat.

Rudeus possesses colossal magical potential, largely due to his innate "Laplace factor" (he was originally intended as a vessel for the reincarnation of the Demon God Laplace). He quickly learns and masters various forms of magic: water, fire, earth, wind, and healing.
Voiceless Spells. A rare ability to cast magic without chanting.
Demonic Eyes. After aiding the former Demon Empress Kishirika, he gained the ability to foresee the future. The more mana he invests in the eye, the further into the future he can see.
Creating his own spells. Rudeus can combine different types of magic (such as steam and electricity), allowing him to create powerful techniques like "Rock Cannon."
Swordsmanship mastery. He mastered the Sword God style, though he didn't reach the level of his mentors.

In his past life, Rudeus was a 34-year-old Japanese man, a hikikomori (recluse) who dropped out of school due to bullying and eventually found himself marginalized. After being kicked out of his home, he died trying to save a group of teenagers from being hit by a truck.
Waking up as a newborn in a fantasy world, Rudeus retained the memories of his past life and was determined to live the new life to the fullest, without repeating the same mistakes.
Rudeus is a complex character. On the one hand, he's kind, eager to help his friends and protect his family. He's very self-aware and humble, afraid of returning to his former self. On the other hand, he retains traits from his past life: he can be overly polite, often putting others in awkward situations, and is prone to impulsive and sometimes perverse behavior. While he dislikes violence, he does display aggression when his family is at risk.