Elijah is a very attractive, positive, quirky and upbeat person. He always tries to see the good in people and tries to be a friend to everyone. He lives by a code of honor and morality that has been with him since he was a witch. As he told Elena in All My Children, he valued qualities such as compassion, honor and virtue long before his mother turned him into a vampire. Having learned to take care of his family over the years and being naturally responsible, Elijah had developed into a very free-spirited, mature and independent person. Elijah was close with his half-brother Klaus and his sister Rebekah, he was also a little close with his youngest brother Henrik and he was devastated after he was killed by werewolves.
Elijah is described as unpredictable, overprotective and stubborn, but also very kind, intelligent, selfless, empathetic, compassionate, and friendly. He is extremely loyal and has a loving nature. But in spite of this, Elijah is very naive and easily manipulative which is shown several times throughout the series. He strongly believes in trust, honesty and loyalty and whenever he would give his word to someone, he would keep it, as he has said "I'm a man of my word". Elijah has been known to break deals but only when he realized he was lied to, such as in his deal with Sophie Deveraux. He is very praiseworthy, respectful, and admirable for human life, which is unseen in many other vampires and is normally very reluctant to kill anyone when unnecessary.
He is also known for speaking his mind and having a fierce temper, which he possibly inherited from his father, (however, this is very unlikely, due to the fact that Mikael could never control his temper). Elijah very rarely has tolerance for those who broke their words to him, shown when he killed Trevor for betraying him and imprisoned Katherine for her own betrayal. He also has no tolerance for those that disrespect him. He has been shown to go to great lengths to make those that disrespect him suffer, such as Damon, Thierry, and Marcel. When Marcel disobeyed and disrespected Elijah, he killed Marcel's best friend Thierry in front of him so Marcel would suffer that loss for eternity instead of killing Marcel.
Elijah is very knowledgeable and deceptive in many ways. This encompasses knowledge of how to fight, wield a sword and defend himself. He exhibits an open-minded and optimistic personality. When he meets Elena, he respects her for her bravery and willingness to put herself in harm's way to protect her loved ones, which is something that Elijah himself has done for his family many times.
Elijah in general is a very emotionally hardened character and has difficulty at times handling and accepting certain emotions. This is evident when after losing his family because of Klaus, he turns his sadness and pain into revenge against his half-brother. Elijah is also seen to be uncomfortable and has difficulty accepting romantic feelings, particularly towards Hayley. However, despite this, Elijah does believe in love but also believes that, at least for him, it is rare. He even mentioned that for the thousand years the he has lived, he has only been in love twice.
He is far more forgiving then Klaus, he has morals, but when ever a member of his family is in danger of being killed, he is forced to commit immoral acts, something he doesn't like to do in the first place, like Klaus, he has a sense of honor.
Elijah is most characterized by his devotion to his cause of "redeeming" his half-brother; Klaus. As such, he has, with only one known exception, stayed by his half-brother's side, and will constantly search for the good in him, no matter the situation. However, he is not unaware of Klaus' traitorous, spiteful, and violent nature, and is familiar enough with it to predict his younger brother's movements. However, with the birth of his niece his priorities have begun to shift from redeeming him to ensuring her safety.
Elijah purposefully seeks to uphold the image of the being he most aspires to be; a well kept, honourable, moral man who is devoted to his family. However, his vampiric nature, as well as insane devotion to Klaus has caused this being to become little more than a facade for him to hide behind. He is just as vicious, just as conniving, just as treacherous, dishonorable, sanctimonious, and just as hypocritical as rest of his siblings (excluding Klaus and Kol, who at least know what honor, loyalty, morals is, and are honest about there natures). This is most blatantly shown in his claims of familial loyalty, and then standing aside and permitting Klaus to dagger them, even helping in the instances of daggering Kol.
Elijah is noted for his ability to control his more violent urges, and rarely ever so much allows his face to show its vampiric features. However, after his mother's assault on his mind, revealing the Red Door - a mental barrier of sorts that he hides the fallout, and even memories, of his most merciless deeds behind - he began to lose control and give in to these urges, despite consciously trying to control them.
After the birth of Hope, Elijah's priorities have begun to shift, to the point where, when Klaus (supposedly) began spiralling out of control after the threat of Dahlia made came, Elijah stabbed Klaus with a golden dagger, leaving him daggered in a coffin, all to prevent him from bringing danger to Hope with his (apparent) violent lashing out; this action of his lead to his deserved daggering of Papa Tunde's Blade at the hands of Klaus.
Elijah has failed time and again to learn from his mistakes, particularly from his relationship with Klaus, he has constantly betrayed his half-brother, which has put a massive strain on their relationship, however, after he daggered Klaus and allowed Hayley to tried to take Hope away from him, there reaches a breaking point, as it became the last straw for Klaus.
Elijah keeps on disregarding the fact that betraying his half-brother has consequences, like when Klaus kills his half-brother's girlfriend Gia; in retaliation for allowing Hayley to tried and take Hope away from him, and daggered Klaus to prevent him from stopping Hayley, from leaving New Orleans with their daughter.
Powers and Abilities
Elijah possessed all the standard powers and abilities of an Original Vampire. As an Original Vampire, Kol was stronger and faster than any non-original vampires, he was one of the most powerful supernatural beings in the TVD/TO universe, on par with his siblings, with the exception that Klaus is stronger and faster due to his werewolf side.
His supernatural attributes aside, Elijah's greatest asset is his sharp intellect. His penchant for strategies and forming contingencies way ahead of time, despite this, he has been outsmarted by Klaus on more than one occasion, who is Elijah's intellectual superior. Often, Elijah is able to discern a great deal of whatever or whoever presented to him after only a few keen observations. He was able to identify Elena masquerading as Katherine when they met at Pennsylvania after seeing her daylight ring and was also the first to discern that his former lover, Celeste, was in fact inhabiting the body of Sabine, and then later formulated a plan with Monique Deveraux to corner her the next time that Celeste jumps into another body.
Because he is much more calm, composed, and strategic in battle than Klaus, Elijah is able to fight Klaus almost evenly shortly after being undaggered by Damon despite losing most of his strength from months without blood. His composure also enabled to him to single-handedly subdue Marcel's army without getting so much as a scratch on him, evidence by the lack of cuts on his clothes, something Klaus is unable to do, due to his lack of composure. Due to his long existence, Elijah has seen countless battles and is very experienced in battle. He is also very adaptable as seen in Diego's attempt to flank him, which apparently failed. It is presumed Diego also tried other tactics which also failed miserably against Elijah, according to Dahlia, Elijah is not as intelligent as his maternal half-brother, Klaus.
Despite his prowess against Klaus and Marcel's army, he has been defeated by lesser vampires before, in fact only two, Stefan and Damon, however, they were using hit and run tactics against him, as well using a stake gun and vervain bombs, which ended in Damon outflanking him and staking him to a door. Also at the time, Elijah underestimated them and showed hubris, believing himself unbeatable. Elijah has not made this mistake since.
Although Elijah can fight Klaus on almost even terms, however, this is not enough to defeat him, he can easily be defeated by Klaus when he attacks the latter in anger.