Jack Kline

Jack is the son of Lucifer and a human woman named Kelly Kline. He is a Nephilim in the CW's hit-tv series Supernatural.

Season 13
After his birth, Jack aged himself into a young as his mother told him while he was in the womb that it can be dangerous for a baby. He knocked the Winchesters out and wandered around to find his father before he wandered through the forest and was taken to jail for help. He met Sam again and thy talked with Jack stating his biological father Lucifer wasn't him but his uncle Castiel was since his mother told. He is told Castiel is dead.

Jack overheard the argument between Sam and Dean before he sadly said Castiel's name, with his eyes glowing in the process. Jack's voice telepathically reached The Empty where the soul of Castiel was sleeping before he awakes hearing Jack calling his name.

In The Big Empty, Jack helped the brothers in a case with a shape-shifter and has the good one help him get closure for his mother's passing and instinctively uses his powers to save Sam from the shifter who was planning to kill everyone which allows Sam to kill the monster. Jack comforts the good shifter by stating she helped him in his pain as she took his words with a smile. Jack is soon given approval from Dean and takes it with a smile.

In Advanced Thanatology, he was mentioned by Sam to have stayed at the Bunker as he and Dean worked on a case.

In Tombstone, as he was on the computer doing research, the brothers returned, he asks how the case went as they revealed they brought a surprise it is a resurrected Castiel. Jack questioned this as he learned that what gets burn stays dead and he is asked if he had something to do with it, as he revealed he begged for Castiel to return which woke him in the empty. Castiel thanked him as Jack was relieved to have him back and hugged his uncle. Jack then revealed he was researching and showed the group a case, which he suspected was zombies. While Dean humored him they decided to go through with it as Jack caught up with Castiel about his not being there for him and that Jack's mother was right about him being good. Jack's research about the case proved correct but it turned out the monster was a ghoul. After finding the monster, Jack tried to help Dean but ended up killing an innocent bystander and fell into a depression. Castiel and Sam tried to comfort him but Jack angrily told them to stop. After Dean killed the monster, Jack felt guilty for his actions as everyone tried to comfort him but he left the group after apologizing for flinging them around.

Jack hid his presence from everyone so he wouldn't be tracked which proved useful as the angels were trying to find him to replenish their number and Asmodeus was tracking him. Once Asmodeus captured Castiel and Lucifer (who returned from the other world), he realized he'll need Jack to help him if an alternate version of Michael invaded.

In the The Bad Place, Jack decided to master his powers and wanted to prove he was good and searched for other realms to find Mary Winchester for her sons as he knew they wanted her back. Jack's search led him to find Dreamwalkers, people who can see other worlds and after meeting one, he found the world Mary was trapped in.

After finding a more stronger dreamwalker named Kaia, he failed in convincing her to join before he was found by Sam and Dean. He told them of his plans before letting them see the vision of the world Mary was trapped in. Mary was shown in a cage being tortured by spikes stabbing her repeatedly as she called out for help. He later revealed to the Winchesters, he was not trying to find Lucifer who he doesn't see as his father or family and that them as well as Castiel are his only family. This comment was met with agreement by Dean who praised him for his actions to save his and Sam's mother, as Jack smiled at these words.

After the angels kidnapped Kaia, they ask Jack to join them and be with his own kind but Jack denied they were his family since they killed innocents and helped the Winchesters in killing them. Dean then forced Kaia (who learned of Jack's family) to join them, Jack apologized to her and they bonded when he showed her a peaceful world.

They soon combined their powers to create a rift, but as a result of Kaia's lack of focus and the angels' attack. Everyone was separated, with Jack being the only one sent to the world that Mary was trapped in as she was confused by his presence and identity while he knew who she was.

In Devil's Bargain, upon finding out that Michael is in the Apocalypse world, the Winchesters and Castiel decide to go back to that world and save Jack as well as Mary from danger. They enlist Donatello Redfield to use prophet abilities to open a rift after reading a angel tablet. Asmodeus also discovers Jack is in the other universe after disguising himself as Castiel and getting information from Donatello.

In Good Intentions, Jack was revealed to have been captured by Michael and his subordinate Zachariah plays scenarios in his mind to get him to open a rift. Jack is trapped in a series of scenarios in attempt to get him to use his powers but he sees through them and meets Michael who subdues him and throws him in a cell with Mary.

He talks with her and reveals his identity as a Nephilim. He tells her that her sons sent him and they aren't present in Apocalypse World and she tells Jack to let Michael kill her since they can't allow him to invade Earth but Jack wanted to rescue her. They escaped when they learn the fortress has a spot of weak warding and the two meet the Alternate Bobby and go to his colony.

Jack entertains survivors but uses his powers which Bobby takes note of and is angry when Mary tells Bobby what he is. Bobby ordered for him to be exiled out of distrust and Mary decides to go with him. The next day, angels invade and Bobby blames Jack since it was him who drew them to him and he tells Jack he can't help. While running Jack hears screams of survivors and remembers what Sam and Dean taught him, he turns back and finds Mary being confronted by Zachariah who overpowers her and demands Jack's location. Jack calls out to Zachariah and uses his powers to immobilize him before he kills the angel in front of Mary and Bobby who just arrived. Bobby alerted Jack of three more angels who were coming and he killed them in mid-air.

In Bring em' Back Alive it was mentioned by Charlie Bradbury that Jack and Mary have formed a resistance against Michael. In the main universe, Gabriel (Jack's uncle) is informed of his nephew who was sent to the other world.

During Funeralia, Jack sees many victories over Michael's forces but mary is concerned about the survivors they are taking in.

In Beat the Devil, Jack reunites with Dean and Castiel before he meets his uncle Gabriel. He is informed of Sam's fate and becomes distraught as Castiel tries to comfort him but he ignores him and questions both his uncles on resurrecting Sam as they tell him they couldn't as they are strong enough. Jack then watches Sam arrive alive and smiles at him before he sees that him being followed by Lucifer who greets his surprised son.

In Exodus, Jack is shocked to meet his real father but Dean stops him from trying to speak with him. Jack watches an argument between everyone break out and teleports away as Gabriel goes to find him. Alone, Jack ponders on his thoughts as he recalls his mother telling him nobody would blame him for looking for his father. Jack returns to camp where he decides to hear Lucifer out, to the latter's delight.

Jack is told of his other family such as Michael and he remarks while he didn't meet his real uncle he met the counterpart who tortured him. Lucifer soon points him out to Gabriel who Jack states he already met and they talk with him as Jack hears his uncle criticize Lucifer and warns him not to trust him.

During Let the Good Times Roll, Jack joined the Winchesters and Castiel in hunting werewolves and they are successful after Jack immobilized them with his telekinesis.