"We don't want you getting in the way again. Count along with me, Isaac. One ... two. Three." - Kali to Isaac Lahey
"You and me Derek, or they tear her apart. What do you say? You think you can beat me one on one?" - Kali to Derek Hale
Kali was, prior to the series, an alpha werewolf and the head of her pack which included her emissary and great love Julia Baccari. Kali was recruited by rogue alpha, Deucalion alongside Ennis, to form an elite pack of alphas. She accepted the offer, killed all of her former pack to join, and was to do the same to Julia, but instead left her to die. Kali became second-in-command of the pack as well as involved with Ennis. In Season 3, Kali, as part of the Alpha Pack, are in Beacon Hills, California to recruit alpha Derek Hale and then Scott McCall who has the potential to be a True Alpha. Kali participates with the alphas' plan to coerce Derek into joining them. They abduct his packmates and family, Erica, Boyd and Cora Hale to lure Derek into a trap, with Kali killing a defiant Erica. The tension between the two packs leads to an all-out-battle. Deucalion lies to Kali that Ennis had died from fighting Derek, and she swears revenge on Derek unless he joins in repentance. The alphas, including Kali redirect their attention to the Darach whom is committing human sacrifices in a move against them. She discovers the dark druid's identity: Jennifer Blake whom is actually Julia, her old emissary having sworn revenge against Kali and the Alphas for attempting to kill her. Kali takes on Jennifer in battle but is overpowered and killed.
Kali is bisexual. She was a formidable, strong-willed and proud woman with a sense of conviction, being the leader of her pack. Kali speaks her mind showing she is blunt to the point of being tactless.
"They killed one of ours!"
"One of yours. Why should I care about one of your pack?" - Ennis and Kali over the Argents' threat
These hot-headed characteristics of hers were most likely what Deucalion coveted so to bring Kali over to his new monstrous cause and recruit her for his new alpha pack. As a result Kali is a savage werewolf, being immensely bloodthirsty, ruthless and sadistic, has a dark sense of humor and displays no remorse for betraying and slaughtering her previous pack, drunk from subsuming their collective power. Like Deucalion, Kali is very smug and fanatical over her immense power and reputation as part of the alphas.
"Tell him what it's like, Kali, to kill one of your own."
Kali has a commanding presence, no sense of fear and is an effective leader, naturally being Deucalion's second. She is very loyal to Deucalion, follows his orders unquestionably even if she doesn't always agree with them as she scoffed at the idea of Scott and Derek joining the Alpha Pack, not considering them worthy of the privilege. At first though however, Kali's loyalty was transmutable: she only joined the pack to be with Ennis at first. Her previous loyalty to her emissary Julia reached far enough to simply leave Julia to die in peace after savaging her, going against Deucalion's order. Typical for a werewolf, Kali is extremely vengeful, blindly swearing revenge against Derek for her lover Ennis' death. Kali's ruthlessness and thirst for vengence, however blinded her in that she paid no heed Marin Morrell's (truthful) claims that her leader was who actually killed Ennis, showing her poor sense of judgement ultimately leading to her undoing. Kali never backed down from Jennifer (Julia) and her impending death.
"I ... I - I should have ... I SHOULD HAVE RIPPED YOUR HEAD OFF!!" - Kali's final words
The packs met at an abandoned distillery outside Beacon Hills. Kali and her packmates accompanied other delegates from neighbouring packs, including members of the alpha Deucalion's pack. Once the meeting commenced, Ennis pointed out the murder site where the Argents executed one of his pack, cutting one of his betas.
Kali: "One of yours. Why should I care about one of your pack?"
Laura Hale: "Because the hunters don't discern packs. Especially the Argents."
A little while later, upon the declaration of war upon Packs by Gerard Argent, Kali was recruited by a spiralling, corrupt Deucalion to form the basis of the the Alpha Pack. Kali accepted, partially to be with Ennis, hinting she and Ennis were in an affair. To join, Kali went on to murder her whole Pack to add all their individual power to hers.
When the Alpha Pack were at the height of their power, Kali rose and became Deucalion's right hand. At the time of Season 2, the Alphas arrived to Beacon Hills having taken notice of Derek Hale's rise to Alpha status.
They captured Erica Reyes, Vernon Boyd and Cora Hale holding them captive at Beacon Hills First National Bank to set a trap for Derek. Erica attempted to fight back, but the malicious Alpha easily killed her.
Kali, wickedly responds they don't want him getting in the way of their objective again, dropping her facade. Isaac, in horror, realizes who Kali is but is helpless as the drug kicks in. Kali stands over the teenage beta gloating sadistically
"Count along with me, Isaac." (Holds up her hand and shifted fingertips) "One. Two. Three."
After Isaac is incapacitated for Ennis to collect him in surgery, Kali then scours the hospital for the other target, the mercenary Braeden. She sees the guarding deputy incapacitated and handcuffed, that Braeden has escaped. Snarling, she retreats out of the hospital.
Kali, along with the whole Pack of fearsome Alphas, infiltrate the high school and corner Braeden, who puts up a decent fight. Kali delivers Braeden the dealing blow. The subordinate Alphas back away as the leader Deucalion confronts their target.
At Beacon Hills First National Bank, the Alphas are stationed for the bait-and-switch trap for Derek Hale. Kali pauses for a short second when Allison Argent infiltrates the bank. Allison evades the malicious Alpha's sense of smell by spilling ammonia to hide her scent. Kali walks on.
Kali holds the pipe in Derek long enough for him to bleed black ooze. Cora shouts at Kali she's killing Derek. Kali talks back saying, "Not yet, little sister" in an endearing but dangerous tone. She advises Deucalion to get to the point. The lead Alpha explains the pitch of his proposition to Derek: killing off his Pack to absorb all their power and strength. Kali smiles sadistically when Deucalion requests she tell Derek feeling to "kill one of your own", and responds "Liberating". Once Deucalion makes his proposition, Kali takes the pipe out of Derek, and the Alpha Pack make their way out of the loft.