WARNING: The following contains major spoilers for Season 5 of Supergirl, with premiered Sunday on The CW.
Season 4 of Supergirl ended with a bombshell revelation from Lex Luthor to his younger sister Lena after she had mortally wounded him. With his dying breath, Lex taunted his killer with the knowledge that her best friend Kara Danvers was actually Supergirl and had kept the massive secret from her the whole time. The news rocked Lena to her core, quickly setting her up as the principal antagonist in Season 5 fueled by her feelings of betrayal and mistrust of the rest of her friends. However, as Season 5 progresses, it is becoming increasingly clear that solid character development for Lena in providing a logical, well-paced heel has been sacrificed to make the antagonistic shift happen as quickly as possible at the expense of any sense of sympathy for the character.
Season 5 kicked off with Lena selling her controlling interest in CatCo, the news media company that Kara and many of her friends have been working at for the entire series, to her old frenemy Andrea Roja. Like literally all of Lena's friends in her life, the relationship between the two women is estranged over feelings of betrayal involving an adventure in Costa Rica the two undertook years ago. Under Andrea's leadership, CatCo veers from hard-hitting journalism to tabloid-esque sensationalism that ultimately drives James Olsen -- Kara's friend and boss and Lena's ex-boyfriend -- to leave National City for good.
While selling off CatCo to someone she knows will make Kara's day job miserable, is a well-measured -- if, well, catty -- way to distance herself from her estranged friends, the full extent of Lena's psychological issues dramatically escalate as the audience gains a wider glimpse at her private life. Using her resources, Lena has created an artificial intelligence program named Hope as the only companion she is completely open and honest with, as she vents her frustrations by just beating down a simulation of Kara...a move that has been used in multiple different Superman media adaptations under similar circumstances by Lex.
Lena's hardened stance becomes slightly conflicted when Kara decides to openly share her superhero secret with her and become more honest with her best friend, but this development is quickly discarded by the introduction of J'onn J'onnz's long-lost brother, Malefic. The wayward Martian secretly joins forces with Lena under the pretense that she can expand his telepathic abilities to control his brother but, faster than a speeding bullet, she betrays him, revealing she has used her experiments on him to develop technology capable of controlling minds...including Malefic's which she uses to terrifying effect before later turning its full force on the DEO.
From the Season 4 finale to the Season 5 premiere, Lena Luthor has gone from a conflicted figure looking to escape and redeem the Luthor family legacy to a sneering villain, every inch as calculating and manipulative as her older brother in a supervillain origin that roughly lasted a matter of months. While flashback sequences have attempted to position the sinister potential within Lena all along, years before her arrival in National City in Season 2, the rapid escalation comes off as forced and rushed, to say the least.
As Supergirl races towards the Arrowverse's upcoming Crisis crossover event, the DCTV series has wasted no time in establishing Lena as Kara's very own Luthor antagonist, with all the mad scientist and spurned businesswoman aplomb as her brother. But, with such a fan-favorite character who sought so much to distance herself and do better than her heritage suggested, the sudden heel turn does bring a sense of ill-paced whiplash at best and a complete disservice to the three previous seasons of progression for the character at worst.
Airing Sundays at 9 p.m. ET/PT on The CW, Supergirl stars Melissa Benoist as Kara Danvers, David Harewood as Martian Manhunter, Mehcad Brooks as Jimmy Olsen and Chyler Leigh as Alex Danvers.