Charles Gunn's History
Early life
Gunn was born in the Badlands, a section of inner-city Los Angeles where the police would not go, and looked after his sister, Alonna, from a very young age. Although he had a few brushes with the law, he acted as a kind of urban Robin Hood to keep the streets in his neighborhood safe. In his teens, Gunn rose through the ranks to become the leader of a gang of street-fighters who protect their turf from vampires using guerrilla tactics. Possessing the mind of a military strategist and the strength of a back-alley brawler, life in the ghetto hardened Gunn to the extent that his own well-being became less important than the cause, resulting in him trading his soul for a truck in a deal with a demon named Jenoff when he was only seventeen, because he believed he had no future.
In 2000, Gunn witnessed the vampire Angel roughing up a blackmailer and tried unsuccessfully to dust him. Eventually, Angel won Gunn's trust, but not in time to save Alonna from being turned into a vampire. Gunn staked his own sister, a decision that would haunt him for the rest of his life. This loss forced Gunn to question his own motives and made him more receptive to accepting Angel's help, as he realized he couldn't do everything alone.
Angel Investigations
Angel recognized Gunn's strength and began on him for back up in battle or protection for the people he cares about when he cannot protect them himself. Although Gunn initially regarded his time with Angel Investigations as a "paying side-gig", Gunn eventually became a full-time member of the gang, gaining mutual respect for those he fought side-by-side with while finding his place in the world. However, his new work often led to conflicted loyalties; Cordelia was accidentally sucked into a portal to Pylea while a member of Gunn's old street crew, George, succumbed to the bite of a vampire. Gunn felt responsible for his friend's death, believing that it would not have happened if he had still been around to help in the fight. Yet even in his grief, he realized that he could not commit the same crime twice and allow Cordelia to suffer the same fate, so he joined Angel, Wesley, and Lorne to rescue her.
A short time after their return from Pylea, demons across the city were being massacred — regardless of their actions — and Gunn came to the conclusion that his old gang was responsible for the deaths. At the time, they were being led by Gio, who had a grudge against supernatural entities because of an unrevealed event in his past. He realized that his ties with his old life were gone and that his loyalty then lay with the vampire with a soul. In a showdown with one of his lifelong friends, Gunn finally choose the mission of the Angel Investigations team. Without realizing it, Gunn found the future he thought he would never have: he had friends, loyalty, respect, and a mission to pursue. He even found love in the arms of the new girl Fred Burkle, but his past still came back to haunt him when the demon Jenoff decided it was time to cash in on the deal Gunn had made years earlier by claiming Gunn's soul. Angel and the others at Angel Investigations were able to aid Gunn and defeat Jenoff, allowing Gunn to live his life to the fullest.
Fred became the most important person in Gunn's world, but Gunn's devotion suffered the ultimate test when he killed Professor Oliver Seidel, the person responsible for deliberately sending Fred to Pylea, in order to save her from having to carry the burden of doing it herself. The guilt of what he had done for her plagued Fred and, instead of bringing them closer together, it began the rut that led to the end of their relationship. Although no longer romantically linked, Gunn and Fred continued to fight side-by-side, and Gunn had a fling with the electric Gwen Raiden. When Wolfram & Hart wanted to cut a deal to have Angel take over the LA branch, Gunn was led into the mysterious White Room where he was exposed to the conduit to the Senior Partners, who impressed Gunn with his immense power. Soon, he underwent a remarkable transformation at Wolfram & Hart.
Wolfram & Hart
Feeling useless and undervalued by his friends, Gunn submitted to a procedure at the hands of Wolfram & Hart's Medical Department that enhanced his mind with a comprehensive understanding of the law (and Gilbert & Sullivan, to help improve his voice and diction), making him the only member of Angel's team able to work inside the system. Gunn grew to love his new job and newfound knowledge, feeling that he could accomplish more now than he ever did before.
His mental abilities began to diminish, so Gunn, fearful of losing his new talents and respect, made a pact with Dr. Sparrow and got a permanent upgrade in exchange for agreeing to release an ancient curio stuck in customs. This curio resulted in the death of Fred and the resurrection of Illyria, and a guilt-ridden Gunn returned to his old street attire and willingly took Lindsey McDonald's place in Wolfram & Hart's Holding Dimension in order to get information on how to stop the Senior Partners. While the team had no clue how to free him, Illyria saved Gunn with ease. He then returned to the fold, changed and seeking redemption for his errors. He slew Senator Helen Brucker, one of the members of the Circle of the Black Thorn, but was badly injured in the process. He then joined in an alley with Angel, Illyria, and Spike to one last fight against the army of the Senior Partners. Illyria stated that he had only minutes to live, and Gunn responded: "Then let's make them memorable."
The Fall
Gunn was badly wounded in the battle and was left by Angel, who was distracted by the chaos of the fight. Dying, he was found by a group of vampires who had been following the visions of a demon and believed Gunn would be a key player in events to come. The leader of the pack sired Gunn, but after rising into unlife, a horrified Gunn killed his sire and took over the vampire pack, convincing himself that he was not like the other vampires and that he could still hold on to himself.
Finding the demon with the visions, Gunn killed him and drank his blood, causing the visions to pass unto him. Believing he was doing the work of the Powers That Be, Gunn set about trying to restore Los Angeles to normal. He attempted to reverse time to before Los Angeles was sent to hell, but on his own he could only create a five minute time loop. He used this loop to trap three Slayers, whom he used to train his men.
Gunn set about trying to fulfill his visions. He believed that the Powers were testing him, and that he was still a hero. Despite this, he gave in to his murderous tendencies and fed on innocent humans. He also grew to harbor an intense hatred for Angel, whom he blamed for his death. Gunn and his followers began to gather powerful magical artifacts. Their first big move was storming a stadium and killing Kr'ph, Demon Lord of Westwood, pinning the blame on Spike.
In addition to stealing a powerful magical artifact in Kr'ph's possession, he also kidnapped one of his slaves, Betta George, a powerful telepath whom Gunn needed for his plans.
As part of his revenge against Angel, Gunn destroyed the Wolfram & Hart building, Angel's headquarters in the war with the Demon Lords. Gunn later bore witness to Angel's defeat of the Lords, hanging back to ensure that not all of the people were slaughtered should Angel fail. Shortly after the team moves back into the Hyperion Hotel, they go looking for the "powerful vampire" that has been amassing magical artifacts. They track down Gunn, who reveals his vampiric nature to Angel.
Gunn begins to give Angel a tour and explains what happened to him, hoping to recruit Angel to his plan. Angel correctly surmises that Gunn is seeking his approval, but when Gunn realizes that Angel is not going to go along with his plan, and when Angel tells Gunn that no matter what he thinks he is, he is nothing more than a demon, an enraged Gunn attacks Angel, and uses a magic artifact to undo the glamour that had been disguising the now human Angel as a vampire, as well as undoing all the magical spells Angel had used to heal himself, leaving him dying.
Gunn decides to let Angel lie there and die slowly, only to be confronted by Wesley's "ghost" who reveals to him that the visions he had been receiving were from the Senior Partners rather than The Powers That Be. Ignoring this revelation, a delusional Gunn proclaims that he may just as well be the subject of the Shanshu Prophecy as the vampire with soul rather than the vampire with a soul. Gunn continues to attack his former friends before he is kicked out of a window by Connor while trying to finish Angel off. He is found by Illyria, and tricks her into transforming into Fred so that he can mortally wound her. Transporting her wounded body back to the altar he had constructed with his stolen magical artifacts, Gunn puts his plan into motion; to transform Illyria back into her true form, and to then use Betta George's telepathic powers to coerce Illyria into winding back time to before the Senior Partners sent Los Angeles to hell.
Gunn's plan seemingly fails, as the Senior Partners reveal that they were indeed the ones sending him the visions, and that they had him construct the magical altar in order to restore Angel to life in case he died. However, Illyria, now despairing over the meaninglessness of existence, decides to go along with Gunn's plans on her own; to a point. She reverts to her true form and maddened by the fact that she cannot become Fred, attempts to do what she believes Fred would do and tries to unravel all of existence, which Gunn simply accepts.
When Angel and the team came to stop Illyria, Gunn tried to fight them off, even killing Connor. Angel spares him however, and stops Illyria by having Betta George implant her with everyone's memories of Fred, making her realize that this is not what Fred would want, and giving the Senior Partners the chance to take her down. Realizing that the only way to save Los Angeles is to force the Senior Partners to restore him to a point in the timeline before Los Angeles went to hell, Angel goads Gunn into killing him, which he does, causing the Senior Partners to turn back time to the battle in the alley.
This time, Angel saves a mortally wounded Gunn before he can be sired, despite Gunn, who still remembered everything he did as a vampire, begging him to let him die. Angel took Gunn to a hospital, where he was saved but slipped into a coma. Angel visited his friend a month later, forgiving him for everything that had happened in Hell.
Post-Twilight
Following the end of magic, Gunn reunited with Angel when he, Faith and Willow came to Los Angeles to ask for Connor's help in a plan to restore magic, Gunn updating Angel on what the rest of the gang had been up to since he last saw them, standing guard at the Earth end of the portal Willow subsequently created into Quor'toth while the others followed to protect Willow while she 'recharged' her magic batteries.
When Willow and the others completed their objective, they returned to Gunn's position and true to the vast time difference in dimensions, it was only some minutes to him.
