Stefan Salvatore

Vampires have fatal weaknesses:
Witch Magic: A powerful witch can incinerate a vampire with a single thought or deprive him of his powers with curses.
The nature of blood

Vampire blood has healing properties for humans - it can cure a fatal wound or disease.
However, if a person dies with vampire blood in their body, they themselves become a vampire.
To survive, a vampire must regularly drink blood (preferably human), otherwise it will begin to lose strength and fall into a coma-like state.
If the person survives (the wound is not fatal)

Vampire blood will act as a powerful medicine.
It will trigger accelerated regeneration: the wound will begin to heal before your eyes, fractures will heal, and internal damage will disappear in a matter of minutes.
The person will fully recover, but will not become a vampire. They will simply receive a one-time super-healing. The blood will be processed by the body, and there will be no side effects.
If a person dies from a wound (with vampire blood in the body)

This is where things get interesting. If vampire blood is present in a person's bloodstream at the moment of death, the transition process begins.
A person doesn't die completely. They fall into a state between life and death. It's like a coma.
What happens next:

1. The new convert has approximately 24 hours to complete the transition.
2. To become a full-fledged vampire, he must drink human blood (any kind, even just a few drops). After this, he finally "dies" as a human and awakens as a vampire with full strength, thirst, and superpowers.
3. If he does not drink human blood within 24 hours, the process will be interrupted and he will die for real - irrevocably.
   Taste of Blood: While in transition, vampire blood causes a person to experience a torturous, uncontrollable thirst. The scent of blood literally drives them insane, and their first reaction is to attack the nearest person.
   Vampires cannot have children because nature itself created their immortality as a violation of the natural cycle of life and death. The price of immortality

A vampire can command people, and they will obey against their will. Stefan used this to erase Elena's memory of the bridge accident.
Limitations: Does not work on other vampires, werewolves, or witches. Vervain in human blood also protects the victim—they are uncontrollable and will burn upon touch.
A vampire can "switch off" their humanity, becoming a cold, ruthless predator. In this state, they feel no guilt, compassion, or love, making them even more dangerous. It's a kind of defense mechanism against emotional pain.
Diet is the key to behavior:

· Animal Blood: Reduces thirst, but makes the vampire more vulnerable and not as strong as their human-blood drinking brethren.
Human Blood: Grants full strength and speed. However, there's a risk of losing control and becoming a "Ripper"—a state where the vampire is unable to stop killing indiscriminately, enjoying it.
· Hunger: Without blood, the vampire weakens, may hibernate, and even begin to hallucinate.
Vulnerabilities

Despite all their power, vampires have fatal weaknesses:

1. Verbena: A plant that causes severe burns in vampires upon contact. When added to blood, it renders a person "unreadable" to suggestion and causes excruciating weakness, paralysis, and pain when bitten.
2. Sunlight: Previously, it killed instantly, but with the advent of a mystical ring (the Day Ring), vampires can now go out into the sun. Later in the series, other methods of protection (such as amulets) were introduced.
3. Stake to the Heart: A regular wooden stake won't kill unless it's made from white oak. White oak stakes kill even original vampires. Regular stakes simply immobilize for a while.
4. Fire: Vampires burn like torches. If left unextinguished, they will burn to ashes.
5. Head Severing: Instant death, regeneration will not help.
6. Wolf Bite: A werewolf's bite is fatal to a normal vampire, causing a poison that cannot be cured by normal blood (requiring an antidote).

Stefan was born on November 1, 1846, to a family of Italian descent in Mystic Falls. His father, Giuseppe, was strict and cruel, but Stefan was always his favorite, unlike his older brother, Damon.

Unlike his rebellious brother, Stefan grew up to be a "good boy": responsible, mature, and eager to please his father. He was very close to Damon, and they protected each other. But everything changed with the arrival of a mysterious guest—Katherine Pierce.
In 1864, Katherine moved into the Salvatore estate. Both brothers fell in love with her, but Stefan developed a special bond. He didn't know she was a vampire. When the truth was revealed, Stefan was terrified, and Katherine compelled him to not be afraid, keep her secret, and drink her blood.

This moment proved to be a turning point. When a vampire hunt broke out in the city, Stefan's father spiked his drink with vervain. Katherine, weakened by the poisoned blood, was captured. Her brothers attempted to rescue her, but Giuseppe shot them both. Katherine managed to escape, while Stefan and Damon, with her blood still in their veins, turned into vampires.
Having become a vampire, Stefan visited his father and, in a fit of hunger and rage, accidentally killed him by drinking his blood. This marked the beginning of his darkest period.

He became "The Ripper"—a ruthless monster who didn't just drink blood, but brutally killed and couldn't stop. He was saved by the vampire Lexi Branson, who taught him to control his bloodlust. From then on, Stefan switched to a "diet" of animal blood to avoid killing people, but he knew the monster inside him could always awaken.
For over a century, he atoned for his guilt. Fate returned him to Mystic Falls, where he saved a drowning Elena Gilbert, who turned out to be a dead ringer for Katherine. Stefan saw in her a chance for a new life and true love. However, the struggle with his dark side, the complicated relationship with his brother, and his own past continued to haunt him.

Stefan constantly puts the safety and happiness of his loved ones above his own.
He is incredibly forgiving of people who have hurt him (especially Damon), and never loses hope for the best, despite his centuries of experience full of pain and loss.
He is constantly immersed in guilt for his past actions, which leads to painful introspection and self-flagellation. Sometimes this prevents him from living in the present.
In his desire to be "good," he can become unbearably self-righteous and look down on those who do not meet his high moral standards.
Stefan often keeps secrets and doesn't tell the truth, believing that this is how he protects his loved ones, although this often leads to more serious problems.