The relationship between the Original Hybrid Klaus Mikaelson and Evolved werewolf Aiden. The two began a working relationship in Season Two of The Originals after Aiden helped Hayley Marshall and Jackson Kenner reunite the Crescent Wolf Pack, of which Aiden was a member. Once Hayley and Jackson, as the Alphas of the each bloodline in the pack, performed the Unification Ceremony that allowed the entire pack, Aiden included, to become evolved werewolves, Klaus began going to Aiden to seek his assistance in matters involving his loved ones being in trouble, such as when Marcel Gerard and his vampires were captured by Klaus' brother Finn, or the threat to his daughter Hope that was posed by his ancient aunt Dahlia, a powerful, pseudo-immortal witch intent to take Hope as payment in a thousand-year-old bargain she made with Klaus' mother Esther in their youth.
Eventually, Klaus sought to help Aiden rise within the pack's ranks so Aiden could eventually usurp Jackson's position as Alpha, as Klaus didn't trust Jackson to lead the werewolves charged with protecting his daughter and believed Aiden to be a more malleable and competent potential leader. However, Aiden's association with Klaus ultimately got him killed by Dahlia, a crime for which Klaus took credit for in order to scare everyone else into fearing him, with the hope that this fear would scare them into obeying his commands with regards to his scheme to beat Dahlia once and for all.
They are referred as "Klaiden" by fans.
Throughout The Originals Series
In Brotherhood of the Damned, Klaus summoned Aiden to Marcel's apartment, where Klaus had just arrived to find that Marcel, Gia, Josh, and the rest of the vampires had vanished after having escaped the boundary spell on the Mikaelson compound. Aiden, worried about his boyfriend Josh, told Klaus he was willing to do whatever was necessary to help, so Klaus instructed him to question the wolves about whether they'd heard any rumors about where Finn would have taken them. When Aiden pointed out that most of the wolves had left for the Bayou to start the preparations for Hayley and Jackson's wedding and Unification Ceremony, Klaus became curious regarding the premarital rites they needed to finish. After Aiden made an off-hand comment about the two Alphas having to smoke a blue calamus root from a peace pipe, Klaus realized that the two were about to perform a divulgement ritual and became concerned that Hayley would expose the secret of Hope's continued existence. Klaus then demanded to know where Hayley and Jackson had been taken before leaving the apartment, giving final orders to Aiden to stay on point while he talked with the bride-to-be.
In They All Asked For You, Klaus approached Aiden at the compound after overhearing he and his Alpha Jackson Kenner having an argument regarding the direction of the newly-evolved Crescent Wolf Pack. Klaus suggested that Jackson didn't fully value Aiden's value to the pack, particularly after Aiden played a huge role in reuniting the pack under Jackson and Hayley's leadership. When Aiden asked him what he wanted, Klaus assured him that all he wanted to do was help him and the pack eliminate his brother, Finn Mikaelson, and suggested that instead of an obvious en masse attack, Aiden and the wolves should instead make quiet, strategic moves against Finn and leave the rest to him to handle.
Aiden took Klaus' advice and brought a group of evolved werewolves from his pack to Lafayette Cemetery in their plan to bring the fight to him, and though they did lose Jerick in their battle against Finn and his father, Mikael, Aiden and the others wolves managed to survive. When Aiden came upon Mikael himself, he told him that Klaus was going to kill him before Mikael's daughter (and Finn's sister) Freya used her magic to cast a pain infliction spell. Upon the wolves' return, even Jackson was forced to admit that it would have been a bloodbath had Aiden not planned their attack as they did, although he was unaware of Klaus' influence in his decision.
That evening, Klaus and Aiden met at the Bywater Tavern so that Klaus could make him an offer. He mentioned the werewolves' history, including that in the past, the Alphas were the leaders of a people who were beaten down by the fact that they were forced to transform into wolves every full moon. Klaus then reminded Aiden that it was a new day for them now that they could control their own forms following their pack's Unification ceremony. He then once again brought up the fact that he didn't believe that Jackson was the right leader for the Crescents, and suggested that instead, they should have an Alpha who was chosen by the wolves themselves to lead them into a new era for their people. When Klaus offered to help him become the new Alpha, Aiden asked him what the catch was, but Klaus assured him that all he wanted was a guarantee that Aiden and the pack would always protect his daughter Hope, stating that she was the only thing he cared about. Aiden seemed tempted by this offer, so Klaus told him he could have some time to think it over and left.
In Save My Soul, Aiden and Jackson were sparring in the Bayou when Aiden suddenly lost his temper and began to show that he was seriously considering Klaus' offer to replace Jackson as Alpha. He argued that to stay the Alpha, you have to be the strongest, and reminded Jackson that if the rest of the newly-empowered wolves began to feel like they were all on Klaus' leash while under Jackson's leadership, then they would exercise the werewolf tradition of challenging him to take his role. However, when Jackson asked if Aiden considered himself to be one of the wolves seeking to overthrow him, Aiden simply told him that he was trying to look out for him, indicating that he was still conflicted about his options.
In Night Has A Thousand Eyes, Aiden was in bed with his boyfriend Josh Rosza when he suddenly received a phone call from Klaus. However, he lied to Josh and claimed that it was Jackson before taking the call, not knowing that Josh was eavesdropping on his conversation with his vampire hearing. Once he answered, Klaus informed him that Jackson had been compromised that morning when the ancient and powerful witch Dahlia used Kenning to possess him while he was out with Hayley and Hope in the French Quarter. Though Klaus assured him that Jackson was fine, he insisted that he could no longer be trusted with regards to caring for Hope, and tasked Aiden with being his "eyes and ears" at the compound with Hayley, Jackson, and Hope while Klaus himself dealt with Dahlia, instructing Aiden to alert him right away if anything important happens. Aiden then begrudgingly did as he was told and went to the compound under the guise of being part of Hope's protection detail.
However, once he arrived, he was immediately approached by Jackson, who asked him for his assistance in getting himself, Hayley, and Hope out of town for Hope's protection, as they had come to the conclusion that it was better to flee, as they believed the feud between the Mikaelsons and Dahlia over Hope had nothing to do with them. Since Jackson was unaware of how long they would be gone, Jackson told Aiden to act as Alpha in his stead. Aiden, torn between his wolf loyalty to his surrogate brother and Alpha Jackson and the powerful and vengeful Klaus, reluctantly agreed to help Jackson by procuring them a getaway vehicle and driving them out of town before Marcel Gerard arrived that night to escort them to their new safe house under Klaus' orders. Later, Josh confronted Aiden about his "sketchy phone call" with Klaus earlier, forcing Aiden to confess that he was currently trapped between his family/pack and someone who could easily kill him, and even Josh had to admit that Aiden had no choice but to do what Klaus said. Aiden ultimately decided to compromise by purposely arriving too late to pick up Jackson, Hayley, and Hope, leaving them no choice but to go with the original plan and go to the safe house. However, Aiden did not reveal to Klaus that they had attempted to flee, not wanting to get his friends in trouble either.
That night, Aiden and Josh met at Bywater Tavern, where Aiden admitted that he was an idiot for having accepted Klaus' offer to displace Jackson as Alpha, and lamented the fact that he didn't say no off the bat. Josh assured him that he would help him navigate his way out of Klaus' deal.
In When the Levee Breaks, Aiden, feeling guilty about intentionally screwing up Jackson's plan the previous evening, went to the safe house at St. James Infirmary to see if he could help Hayley and Jackson with their plans. Hayley then got the idea to have the Harvest witch Davina Claire transfer the dark magic in The Cursed Shackles into a smaller bracelet that Hope could wear to stop her from unintentionally doing magic, which was how Dahlia was able to track her. Aiden immediately volunteered to help and sneaked into the compound to steal the shackles from Klaus' study. However, on his way out, he ran into Klaus, who wasted no time asking him why he was there, forcing Aiden to lie that he had been sent by Hayley to get Hope's favorite stuffed rabbit, which they had forgotten when they left. Klaus seemed to believe his story and stated that Aiden was a loyal person, but added that if he disappointed him in any way, he would come to regret it.
When Aiden met up with Jackson to give him the bracelet Davina made for Hope, he ultimately confessed to his role in ruining their plan to run the night before, and explained that Klaus had roped him into spying for him by offering to make him Alpha. Jackson was initially so mad that he punched Aiden in the face, but after he got it out of his system, Jackson acknowledged that Aiden risked his life to help them in the end, which is all that mattered. Aiden, still feeling ashamed for betraying Jackson, who had looked after him his entire life, stated that he didn't feel right being in the pack anymore, and informed him that he was leaving town, but Jackson promised he was always welcome whenever he decided to return. Jackson and Aiden said their goodbyes, not knowing that Dahlia had overheard their conversation from a nearby alley.
Aiden later stopped by a flower shop to pick up flowers for Josh when he was approached by Dahlia, who used magic to kill the flowers in his hands before casting a spell that sliced his face and chest open to appear as though he had been attacked by a werewolf or a hybrid. When Aiden asked her why she was doing this to him, Dahlia admitted that she needed to set the Mikaelsons against each other, and stated that Aiden would be the perfect kindling to achieve that goal. She then used telekinesis to rip Aiden's heart from his chest, a method of execution commonly used by the Mikaelsons. Just as Dahlia intended, Aiden's body was found by Josh and Davina, who immediately contacted Jackson about it. Jackson then brought his body to the safe house, where he immediately accused Klaus of killing Aiden in retribution for exposing his plan earlier. Hayley, Rebekah and Elijah had no trouble believing that this was the case, and Klaus, who felt as though his plans were getting out of control, took credit for Aiden's death in an effort to scare everyone into following his orders, Klaus was clearly (secretly) upset over Aiden's death. However, this ultimately played right into Dahlia's hands, because Jackson, Hayley, and the Crescents turned against Klaus, and even Klaus' own maternal half-siblings believed that Klaus' alleged murder of Aiden was so out of line that they utilized the golden dagger that Davina and their brother Kol had made to neutralize Klaus so they could enact their own plan against Dahlia, neutralizing Klaus ultimately turned him against Hayley, Rebekah and Elijah.
In Ashes to Ashes, Klaus avenges Aiden's death when he kills Dahlia, albeit killed her to protect Hope from her.
- Aiden and Klaus are both descendants of ancient, established werewolf packs that are believed to have existed since the beginning of the werewolf species; Aiden is a member of the Kenner bloodline of the Crescent Wolf Pack, whereas Klaus is the son of Ansel, the former Alpha of the North East Atlantic Pack.
- Coincidentally, the Crescent Wolf Pack and the North East Atlantic Pack are said to have been fighting each other since the genesis of their species.
- Klaus offered to help Aiden become Alpha of the Crescent Wolf Pack (in order to protect Hope) when he found that he disagreed with Jackson's style of leadership and his lack of respect for Klaus' orders.
- Though it was truly Dahlia that killed Aiden with the intention of the murder being blamed on Klaus, Klaus ultimately took credit for Aiden's death and claimed that he had done so because Aiden betrayed him by exposing their plan to Jackson. Despite this, Klaus was secretly upset over his friend's death.
- However, before Klaus was daggered by Elijah in When The Levee Breaks, he confessed to Camille O'Connell that he did not actually kill Aiden, but stated that even if she told others the truth, no one would believe her. Despite this belief, Cami did indeed tell Elijah that Klaus did not kill Aiden in City Beneath The Sea, and Elijah then informed Marcel and Hayley of this news. Unfortunately, the revelation of Klaus' lack of involvement in Aiden's murder did little to change Dahlia's intended outcome.
- Unlike most werewolves from the French Quarter of New Orleans, Aiden was never hostile towards Klaus and had respect for the latter, but at the same time he was terrified of Klaus.
- Despite the fact that Aiden was a member of the Crescent Wolf Pack, who the North East Atlantic Pack, Klaus' pack do not get along with at all, Klaus and Aiden still became friends.