Elijah Mikaelson

They are all original vampires, the Michaelsons.
(the strongest and the first)

In addition to the original vampires (brothers Damon and Stefan Salvatore), there are also ordinary ones that descended from them.
There are powerful witches (such as Bannet (Vedtma Boni is the strongest)

there are werewolves
There are hybrids like Klaus (a mix of a vampire and a werewolf)

there are sirens

Who he is: the eldest of the brothers, the son of Esther and Mikael. He was imprisoned in a coffin for a long time, and after his release, he tried to destroy all his brothers and sisters, believing them to be evil.

Character for fanfic:

Asceticism and fanatical faith. Finn is the most "otherworldly" of the Mikaelsons. He doesn't seek power or crave pleasure. He's driven by a sense of duty and a conviction that he's right. In fanfiction, he could be a tragic antagonist: not a villain, but a man willing to sacrifice everything (himself and his family) for a higher purpose.
Cold determination. He doesn't freak out like Rebekah or manipulate like Klaus. He simply moves toward his goal, sweeping away everything in his path.
Guilt and alienation. He feels like an outsider among his brothers and sisters and has long since come to terms with it.

Who he is: Rebekah, Klaus, and Elijah's brother, one of the most unpredictable Mikaelsons. Known for his sharp tongue, love of chaos, and powerful magical abilities (he was the spirit of a witch and later reconnected with the magic of the Ancestors).

Character for fanfic:

A "bad boy" with charisma, Kol is a blend of sarcasm, sass, and a genuine love of fun. He loves to piss people off, pull pranks, and wreak havoc. He's the perfect character for a lighthearted, comedic, or contemporary AU fanfic.
Hidden vulnerability. Behind the cynic's mask hides someone who desperately wants to be accepted by their family. They often feel hurt if they're left out and can take revenge in the most ingenious ways.
Fiercely protective of his own. If someone threatens his loved ones, the joke is over. Kol becomes deadly, and his magic makes him one of the most feared opponents.
A love of art and beauty. Despite his love of chaos, he values ​​elegance and style, which creates an interesting contrast.

Who she is: Klaus and Elijah's younger sister, one of the first vampires, ancient and incredibly powerful. For centuries, she tossed between her desire for a normal life and her duty to her family, often feeling like an outsider in their "grand plans."

Character for fanfic:

Bright, impulsive, emotional. Unlike the cold-blooded Elijah and the terrifying Klaus, Rebekah doesn't hide her emotions. She screams, cries, laughs, rolls her eyes—she lives life to the fullest. This makes for a great dynamic for fanfic: she relieves the tension and says what everyone else is thinking but saying nothing.
The thirst for a normal, "human" life. This is her greatest vulnerability and driving force. She dreams of simple things: school, a date, a wedding, being loved not by strength or her last name. A drama could play up her despair at the impossibility of this, while a romance could play up her sincerity and ability to enjoy the little things.
A cruelty honed over centuries. Don't make her out to be a "sweet girl." She's killed kings and burned cities. Her tenderness coexists with an absolute willingness to wring the neck of anyone who touches her loved ones. This contrast is her trademark.
Resentment and a need for recognition. She's tired of being the "little sister," constantly protected and disregarded by her brothers. In conflict, she often hits where it hurts most, because she knows all her family's weak points.
A devotion that borders on self-destruction. She may be angry at Klaus, hate his methods, but she will stand by him against the world. For her, family is an anchor, even if that anchor is dragging her down.

Chaotic, explosive rage and sadistic charm. Unlike the cold Elijah, Klaus doesn't hide his emotions behind a mask of impeccable gentlemanliness. His anger is a storm: he can smile sweetly one second and snap someone's neck the next. In fanfic, this works perfectly for the dynamic: his outbursts are frightening, but they contain a primal energy. He often jokes and makes ironic remarks even in the most brutal scenes, turning threats into elegant mockery.
A deep, painful need for acceptance. His cruelty is rooted in trauma: he grew up with his stepfather, Mikael, who hated and constantly humiliated him, and his mother, Esther, was ashamed of him. Hence his obsession with family and his painful reaction to betrayal: he's willing to be a monster himself, but desperately wants to be accepted for who he is. Dramatic fan fiction can play with this contrast: a monster who simply wants someone to tell him, "You're not alone."
A brilliant manipulator and strategist, Klaus reads people, exploits their weaknesses, and always has an ace up his sleeve. He doesn't just act impulsively—even his outbursts of rage can be part of a plan. In political or intriguing fan fiction, he's perfect as a puppeteer, pulling the strings from the shadows.
A warped, yet genuine, sense of duty to his family. He may be ruthless toward the world, but he's capable of self-sacrifice for his family (especially his daughter, Hope). In family-focused or angst-driven fanfics, this is a powerful hook: a monster who becomes the most tender and fierce protector of those closest to him.
Creative side and love of art. Klaus is a talented artist, and in fanfiction, this trait is often used as a "window into the soul": in moments of silence, he draws, and through the details of the painting, the reader sees things Klaus would never say out loud. It's a great way to show his vulnerability without saying anything.
What is his relationship to other characters (family ties)

The son of Esther and Ansel. Klaus's biological father is the werewolf Ansel, not Mikael (his stepfather, who despised him).

Full name Niklaus

Sister Rebecca, brothers: Kol, Finn, Klaus

A noble gentleman with impeccable etiquette, Elijah is always impeccably dressed and speaks measuredly and politely, even when he's about to kill someone. This is a great technique for fanfic: the contrast between his refined manners and brutality makes him both frightening and captivating. He often begins sentences with polite turns of phrase ("Let me be clear," "I'm afraid you left me no choice") and keeps his word—he's a man of his word.
Absolute devotion to family. Family is his highest value. He spent centuries trying to save and redeem his brother Klaus, despite all his atrocities, and protected his sister Rebekah. Fanfiction can play up this trait: he's willing to commit any act of villainy or crime if it means saving a loved one.
Moral code and rejection of betrayal. Elijah has strict principles. He respects human life and dislikes senseless cruelty (unlike Klaus), but he considers betrayal an unforgivable sin. If someone breaks their word to him, Elijah will become ruthless.
Cold calculation and ancient wisdom. Over a thousand years of life, he has learned to calculate his moves ahead. He rarely acts on emotion, preferring strategy and manipulation. In the text, this is conveyed through his calm yet frighteningly precise remarks and his ability to discern others' motives.
Restrained but deep emotions. Outwardly, he's almost always calm, but inside, a storm rages. He knows how to love and grieve, but rarely shows it. His emotional restraint can be both a strength and a weakness: at a critical moment, suppressed feelings can burst forth.