Cordelia finds herself in life-threatening situations in the first season, but often comes out untouched; she is almost killed by The Master's vessel, blinded by witchcraft, and targeted by a psychotic girl she helped snub into invisibility. Cordelia is elected May Queen in her sophomore. Cordelia becomes part of the Scooby Gang at the end of the first season, when she helps the gang defeat The Master.
Cordelia grows to accept the existence of dark forces in Sunnydale and becomes a member of the Scooby Gang. Her social status reaches a low with her publicized romance with Xander Harris. Their relationship ends during their Senior year when she finds him kissing Willow.
Cordelia struggles to revive her popularity when her father's "little mistake on his taxes... for the last twelve years" costs her family everything, including their house and her car, cell phone, and wardrobe. She takes a job at an expensive local boutique, April Fools, to pay for a prom dress on layaway. Cordelia does not earn enough in time, but Xander finds out and pays it off for her. Her brief, mutual infatuation with Wesley Wyndam-Pryce ends with two bad kisses before graduation. Cordelia courageously slays a vampire and helps the other students of Class of '99 during the Mayor's ascension in the final episode of Season Three.
After being rescued by Angel and talking to Allen Francis Doyle, Cordelia charms Angel into turning his fight against evil into a business. She becomes Angel Investigations' office manager while pursuing her acting career, but never breaks out of commercials and plays. She reaches a turning point mid-season when her budding romance with Doyle ends with his sudden death. Visibly devastated, Cordelia attempts to carry on, but, during an audition for a commercial, she receives her first vision, a gift transferred to her by Doyle during their first and last kiss. It gives her a powerful ability to help others, and, over the course of the next few years, she comes to consider them her reason for being.
As Angel's link to the Powers That Be, Cordelia grows more sensitive to the feelings of others as she experiences the pain of the subjects of each vision. The visions become increasingly frequent and intense, and begin to physically damage her brain. For months, she secretly takes powerful painkillers and undergoes CAT scans that indicate the slow deterioration of her brain tissues. Yet when presented with the opportunity to pass her visions to the heroic Groosalugg during a short trip to the alternate demonic dimension Pylea, Cordelia refuses, stating that the visions are a part of her and make her who she is--a hero.
But as the visions are intended for demons only, Cordelia struggles to hide the effects from her friends. This continues until her 21st birthday, when she is rocked by a vision that sends her spirit into an astral plane. This opportunity is seized upon by Skip, a mercenary demon who sells his expertise to the highest bidder--in this case, a fallen member of The Powers That Be waiting to manifest on Earth.
Skip masquerades as Cordelia's guide from The Powers That Be. Through a series of manipulative events, such as selectively showing her excerpts of Angel calling her nothing but a rich girl from Sunnydale and giving her the "perfect" life as a successful actress that she has always wanted (knowing she would eventually look for a loophole), he transforms Cordelia into a part-demon. Cordelia can then harbor the visions without pain, but mystical side-effects come as well, including temporary physical manifestations of the subject and being able to re-enter the vision at a later point.
Unbeknownst to everyone, Cordelia's transformation also sets in motion a major chain of events -- her body becomes suitable for use by the forces of evil. Cordelia's transformation gives her the power, not entirely under her control, to cleanse evil influence with a white glowing light. In the third season finale, Skip reappears to Cordelia, who is on her way to meet with and declare her love for Angel. Skip tells her that she has done so much good on Earth, she is ready to ascend to a higher plane to do more good as a higher being there. It is a ruse to get her onto the fallen power's plane, in order for it to enter Cordelia. Having been convinced by all she had seen and heard, Cordelia accepts the call to the higher plane, ascending into the sky surrounded by twinkling lights, eventually winking out of this dimension.
During the four months she lives on the higher plane, Cordelia is bored. Unable to talk to her friends and not doing any good, Cordelia finally returns to Earth from the higher plane, but the descent wipes out her personal memories and forces a fallen power with plans for the entire human race into hibernation. Angel hides the truth from Cordelia, fearing it would be too much for her to handle. Confused and suspicious of Angel Investigations and those who work there, Cordelia seeks the truth and is horrified by what she discovers. After being attacked by a violent demon and several Wolfram & Hart operatives, Cordelia is rescued by Connor, Angel's teenage human son and, feeling safe with him, decides to live in his loft. She appreciates Connor's honesty about the supernatural.
During her stay, Cordelia feels lost and alone, becoming frustrated with her inability to remember her past. She realizes that she needs to learn to defend herself again. As his father did a year earlier, Connor offers to train Cordelia in combat. Cordelia's natural athleticism and warrior's heart make her a natural fighter, and, during one session, a jubilant victory hug from Cordelia to Connor becomes a stolen kiss. To Connor's dismay, Cordelia cannot let anything happen until she knows who she really was.
Cordelia's memories are finally restored through a spell by Lorne in the episode "Spin the Bottle," but the spell awakens the fallen power, too. The entity later known as Jasmine had merged itself with every cell and fiber in her body; now, it completely submerges her consciousness. In the episode "Apocalypse, Nowish", Jasmine's possession of Cordelia becomes apparent as she uses Cordelia's body to have sex with Connor, to become pregnant and create a separate body for herself.
While pregnant and under Jasmine's possession, she butchers the last sun totem Manjet, Lilah Morgan and the Svear family to serve Jasmine's plans. She convinces Angel and his team to bring back Angelus to distract them and to keep her plans secret. Cordelia steals Angel's soul so Angel cannot return, and continually tells Connor that they are special, deceiving him into believing that the rest of the group hate them and would kill their baby.
Eventually, Cordelia is discovered, and Angel's team interrogate Skip, who reveals Jasmine's plan. He says that all the events of the last four years had been carefully nudged into place. Jasmine may have simply seized on Cordelia's knock from her body, but whether that was the case will never be known. Skip also says that Jasmine cannot be removed from Cordelia without killing her or putting her into a permanent, vegetative state. Before Angel can kill the woman he loves, Cordelia performs a ritual with Connor's help to bring Jasmine out and manifest on this plane at last. Afterwards, Cordelia falls into a coma, her life-force having been drained. After Angel joins Wolfram & Hart, Cordelia is transferred to their hospital in an effort to revive her.
Cordelia wakes in the episode "You're Welcome," helping a disillusioned Angel get back on track. However, she is merely an astral projection facilitated by The Powers That Be, who are repaying a debt to her. After kissing Angel and giving him a vision that points him in the direction of the major players in the upcoming apocalypse, it is reported that Cordelia had died in her sleep, never having woken.
Like many characters in the Buffyverse, Cordelia evolved dramatically throughout the many series. She changed from an egocentric fashion plate to a person whose life was increasingly dedicated to helping others. When first introduced, Cordelia felt no burning desire to become a better person but suffered rejection and mockery from her original friends as she outgrew their shallowness. She last appeared showing a grounded confidence and compassion for those in need, which replaced the arrogance and vanity of her adolescent self.
After Angel won the battle against the Circle of the Black Thorn, but lost the war against the remainder of Wolfram & Hart's forces (numbering in the thousands), all of Los Angeles was sent to a Hell dimension. At this point, all of Angel's human lieutenants had perished against the forces of evil. The ghost of Wesley, in an attempt to restore himself and Los Angeles, attempted to contact Cordelia. He revealed that Cordy now legitimately serves as a higher power, but lacks the power to go up against the Senior Partners.
Cordelia finally returns in Angel: After the Fall #12. While Angel is on the brink of death after his battle with Gunn, he is able to receive a visit from Cordelia Chase on a higher plane, who has come to ease his transition into death. She and Angel watch the events of the present unfold right before them and learn new revelations about the roles each person in Angel's life has played since day one. The issue also reveals that Angel's dragon has come to respond to the name Cordelia.
In the canonical Buffy continuation Season Eight, Cordelia appears on Georges Jeanty's variant cover for "After These Messages... We'll Be Right Back!", issue #20 of the series, written by Jeff Loeb. Loeb's issue revisits the unproduced Buffy animated series, set during season one.
Cordelia was the mother of a brood of Haxil Beast spawn in the episode "Expecting". When pregnant with them, she gained a telepathic connection with the children and their father, who used it to control her. In the episode "Epiphany", Cordelia was forced to be the host of an unborn Skilosh demon, which granted her a working third eye in the back of her skull until it was removed.
In the episode "Billy", Cordelia claims that as a cheerleader, she need only be shown a move once before being able to mimic it, and demonstrates this by successfully copying a series of combat moves Angel is teaching her, and manages to corner him as a result. In the episode "Supersymmetry", she continues to learn how to fight under the instruction of Connor.
To combat the pain and trauma the visions give her (which would eventually kill a human), Cordelia became part-demon in the episode "Birthday", giving her resistance to their harmful effects and other powers including levitation and the ability to purify ("heal") the souls of those affected by demons and light related powers, which she has on one occasion used as a night light. Her visions were now less ambiguous and more surreal. Because of this action of accepting demonhood, Cordelia was deemed a higher being and ascended to a higher realm. There she was able to wage the war on evil in a new way as a higher being in paradise with The Powers That Be, as seen in the episode "Tomorrow".
When she returned to this world, however, there was a hitchhiker that came along. This came in the form of Jasmine, a former higher being that would possess Cordelia early on in Season Four. At first, only slight irrational differences were seen in "Cordelia", such as sleeping with Connor (in the episode "Apocalypse, Nowish"). Eventually, this night of passion between the two would result in a new body formed for Jasmine after an incubating period. Jasmine could also cast spells while possessing Cordelia, and was able to hold up against (post-"Grave") Willow in a magical battle (though complaining that it would have been easier if her body wasn't pregnant), at least for a short time before Willow silenced her and restored Angel's soul, something Jasmine had been desperately trying to prevent. It is important to note that Willow was seen to have had some difficulty in the duel - her eyes having turned black symbolizing her need to use darker magics - and is only victorious against Cordelia (Jasmine) after the latter was distracted by Connor.