|Born||August 1, 1647 (18/364)|
|Species||Vampire (Julianna's Bloodline)|
|Family members||King Charles II (Older Half-brother; deceased)|
|Cause of death||Broken neck (as a human)|
|Killed by||Julianna Monroe|
|Played by||Luke Mitchell|
When Mal-El and Julianna were traveling in England, they came across the younger bastard brother of King Charles II. When Mal was entertaining the king with tales of his exploits, Sebastian became infatuated with Julianna. Unbeknownst to Sebastian, Charles also desired her. When Charles learned of this he had Sebastian beaten to death and thrown into a river to die. Sebastian was saved by Julianna and she then turned him into a vampire.
He has good control of his emotions, though he can become angry when the safety of his friends are threatened.
- Super Strength - Vampires are much stronger than humans and grow stronger with time.
- Super Speed - Vampires can accelerate their movements to cover short distances in an instant, faster than the human eye can see. When running across long distances, they appear as vibrating blurs of motion.
- Emotional Control - Like all vampires, Sebastian has the ability to switch off her humanity.
- Super Agility - Vampires possess superhuman stamina, flexibility, reflexes, agility, and dexterity. They can move, jump, climb, and run incredibly fast without difficulty or exhaustion. This ability improves with age.
- Super Durability - Vampires can take far more damage than normal humans.
- Dream Manipulation - Vampires can control dreams and subconscious. The vampires can produce and modify dreams, bestow nightmares or lucid dreaming. Other effects of this ability is the distortion of reality and trapped in the dreams.
- Heightened Senses - They can hear whispered conversations, even ones in far off buildings, smell blood, and see in total darkness.
- Immortality - A vampire stops aging once turned. Upon their transformation, vampires then on become immune to all conventional illness, disease, virus and infection.
- Accelerated Healing - Vampires can snap their finger bones back into place after being broken and have been seen to fully recover from gunshots, stab wounds, and torso impalement.
- Day Walking - Sebastian has the ability to walk in the daylight through the use of his daylight walking ring.
- The Cure - If he takes the cure than he will become human again.
- Vervain - The act of exposing or ingesting a vampire with vervain causes a vampire to become severely feverish and weak. Also, If a vampire's skin is exposed to vervain, it can result in burning them. Also vampires can't compel anyone on vervain.
- Sunlight - In the sunlight he will begin to burn and then die.
- Stakes - A wooden stake through the heart will kill him.
- Invitation - In order to enter any house owned by humans, they need to be invited by a person that officially lives there or the person of entitlement. Once invited the vampire cannot be uninvited. If a vampire lives in a house, other vampires can enter freely and if a vampire is in the house without being invited in it will become disoriented and will begin to suffocate.
- Magic - Vampires are susceptible to the powers of witchcraft including the creation of harmful magical objects. It is said a witch with enough power can kill a being as powerful as an original but its never been proven.
- Desiccation - Being completely drained of blood or the heart stopping will cause an original vampire to desiccate like any other vampire, lose most of it's strength and any ability to move. The desiccated original will appear as a corpse and can only start functioning again once they feed on blood. This proccess can be replicated artificially by a witch casting a desiccation spell.
- Werewolf Bite - The bite of a werewolf is extremely lethal to vampires.
- Vampire Bloodline - If Julianna dies then he will die.