Isla Kennedy

 is a very powerful witch as well as an original vampire, and Silas' right-hand woman. Her magical power allows her to do the strongest and most dangerous spells with rather ease. She's very loyal to Silas, and would even die for him. According to Isla, Silas never used his mind control over her, because he never needed to.

She's going to be the main antagonist of the second season.

Background
Aside from being a witch, Isla also comes from a family of Guardians, but she was never one. Instead Isla's twin sister, who was born before her, was given the responsibility, leaving Isla always jealous. Her sister later died at childbirth. Even though the Guardianship would pass on to her child, Isla would act as the surrogate Guardian until the child comes of age. It was during that period when Silas found Isla.

By the time Silas came back to life and found Isla, she was already a powerful witch, who even successfully de-aged Katherine Pierce after she unwillingly took the cure for immortality and began aging rapidly. However, as the cure would have to be a stabilizing agent for her spell, it meant that Katherine had to continue her life as a human, as the cure stayed in her body. If she lost it, by severe blood loss or other means, she would once again age rapidly. Unaware that Katherine is a doppelganger, Isla requested to keep some of her blood to keep working on the cure, hoping that maybe one day she could create a better solution. Isla also put a protection spell on the cure to protect it (and Katherine) from any witch that might be looking for it.

Years later, when Silas found Isla and revealed he knows about her family, Isla was reluctant to trust him. But sensing her darker tendencies, Silas decided to stay close but wait for his moment. When she eventually let him in, he not only showed her the true limits of her magic, but also helped her realize what she thought she could do was only the tip of the iceberg compared to what she could actually do. In time Isla began to see Silas more than a mentor and friend, and her commitment soon turned into devotion.

The following years, they grew closer to each other, and eventually fell in love. However, Isla felt as she was aging, it would be impossible for them to be together. Silas didn't want her to become immortal, as it would mean she would have to lose her magic, the thing that makes her special. Upon this, Isla made a few alterations to the vampire creation spell. The lack of white oak forced her to channel her immortality to gold, and she used the cure in Katherine's blood [that she kept] to trick her spirit into thinking it was still a witch, while the rest of her body would act as a vampire. Little did she know at the time, that is was actually Katherine's doppelganger blood that made the spell a success.

Becoming a vampire not only increased her magical capacity significantly, but also enabled her to channel to unlimited energy without having to harm herself.

Realizing she had great power as a vampire, she attempted to "revamp" Caroline, the vampire Silas brainwashed into being his minion, into a stronger, harder to kill vampire. She fed her some of her blood, and staked her through the heart, thus killing her with her blood in her system. Much to Silas' surprise, it worked. Not only now Caroline was far stronger, her life was also tethered to Isla's, meaning if she died, so would Caroline.

Season Two
After Caroline failed to bring the Guardian's power, Isla suspected Stefan or April might have taken out Caroline and taken the power for themselves. But when she went after them, she was surprised to see Caroline among them, freed from Silas' influence and trying to move on with her life.

At the end of the season, Isla engaged in a fierce battle with the team. Realizing there was no other way to beat her, Caroline used a golden dagger (forged from April's medallion which was enchanted by Cassie) to neutralize Isla. However, as she was a vampire that used a dagger to neutralize an original, she too died on the spot.

Season Five
TBA

Towards the end of the season, Isla, in an effort to tear the team apart, goes after Jeremy and kills him, without knowing about the hunter's curse. For reasons uncleared (most likely because she is a vampire created by a different spell), hallucinations start almost immediately, which drives her crazy and unable to seek help from Silas, who previously killed a hunter but managed to overpower the curse. Eventually she undoes her vampire spell and kills herself.

By killing Jeremy and then herself, Isla, without realizing, formed the two corners of an expression triangle (a powerful magical field which, when channeled by a competent witch, does everything the witch can think of if their will is strong enough), which the team later completes and uses to defeat Silas once and for all.

Powers and Abilities

 * Basic vampire abilities: As a vampire, she possesses all basic vampire powers, such as agelessness and enhanced senses, as well as super speed, strength, stamina, healing and endurance.
 * Immunity: As she was turned with a different vampire creation spell than the usual, she is not hurt by sunlight, fire, vervain or wooden stakes of any kind.
 * Unlimited magical capacity: Even though channeling to too much power could still potentially be harmful, her vampire side healing in mere seconds allows her to channel to unlimited power without having to suffer from any of the damages. She still suffers from an after-effect after certain powerful spells, but it is merely a headache.
 * Revamping vampires: If a vampire dies with her blood in their system, they come back as an even more powerful vampire.
 * Unbound to invitation: Even though she is a vampire, her witch side is not bound to invitation when entering a property.
 * Lethal blood: Unlike the regular vampires, whose blood heal/turn normal humans, her blood has complete opposite effect. If taken by a human, it causes blood poisoning. After a while the organs shut down and eventually the human dies before the blood can leave their systems. It's effect on vampires, and other supernaturals in theory, while still poisonous, are not as lethal.
 * If a human ingests Isla's blood, they will have not more than 2 hours before the blood makes any permanent damage to the body for them to die and come back to life as a revamped vampire. After 2 hours, the damage is simply irreversible and the death becomes inevitable.

Weaknesses

 * Lacking vampire abilities: As she was turned with a different vampire creation spell than the usual, she doesn't have mind compulsion or dream manipulation abilities.
 * Enchanted golden dagger: Much like a silver dagger that was used to neutralize the first originals, an enchanted golden dagger is the only known thing that could stop her.
 * Supernatural blood: Even though it doesn't cause any immediate danger, blood from any supernatural species disorients her. The only supernatural blood she can consume is her own.
 * Hunter's curse: Like other vampires, if Isla kills a hunter, she will begin having hallucinations that will push her all the way to suicide.
 * The Cure: As with all other immortals, ingesting the Cure would render her mortal, with no way to become a vampire again.
 * Werewolf venom: It is currently not known whether or not she is immune to werewolf venom, because she has never been in a position to find out. However, it is safe to assume that similar to the other originals, the venom will be poisonous, but not lethal.
 * Her own magic: It is revealed that when Isla created the vampire spell, she also built in a safety in case she ever needed to reverse her vampirism. The reversing spell can only be done by Isla, making her the only person that can destroy herself.

Trivia & Notes

 * Isla is the first witch in the series who is also a vampire.
 * Isla is also the second known guardian in the series.
 * She claims Silas never used his mind control on her, because he never needed to.
 * Isla is the second character in the universe (first in Stefan's Diaries) who is named after their actor. The first was, played by.

Behind the Scene

 * This character was going to be named after it's actor's regardless of who was cast.
 * Other actresses considered for the role were, , , and . The role was eventually given to Fisher, as the writer felt "she is simply perfect for the role".
 * This is the second role Fonseca was considered for but didn't get, first one being the main character April Young.