For three seasons of the CW hit Charmed, Cole was a perfect villain/love interest for the trio of Halliwell sisters, so why did the character die in season 5? Half-man, half-demon, and all dreamboat, Julian McMahon's Cole was a pivotal part of Charmed's third, fourth, and fifth seasons. A huge hit for its producer, 90210 creator Aaron Spelling, Charmed was the Craft-inspired story of a family of three good witch sisters balancing modern life, love, and demon-slaying in contemporary San Francisco.
Green-lit on the back of Buffy's success, Charmed brought a similar style of sardonic charm to its soapy supernatural plot. The show followed Prue, Piper, Phoebe, and eventually, their late-arrival fourth sister Paige as they navigated both their duties as good witches and the responsibilities of modern life. Of course, there was always plenty of time for love interests too, particularly if they were of the former foe variety (just as Buffy had Angel and Spike). And that's where Cole, played by Julian McMahon, came in. Joining Charmed in its third season before Prue was killed off, Cole began life as a villain hell-bent on finally vanquishing the girls and their good magic.
And that's "hell-bent" in the literal sense, as Cole was a powerful half-demon hybrid. But even he wasn't strong enough to resist the allure of the sisters, and soon Cole was reformed into Phoebe's love interest. The pair married in season four, which made it all the more shocking and heartbreaking for fans when Cole returned to his caddish origins and became the source of all evil in season five. This soon led to his death at the hands of the combined powers of the Halliwell sisters. But there's still the question of why the character was killed off after undergoing an engaging redemption arc. As is always the case in television, the truth seems to come down to the bland reality of scheduling conflicts.
Although the actor remained tight-lipped about the reasons behind his exit, it seems most likely that McMahon's starring role in super-producer and later Glee creator Ryan Murphy's Nip/Tuck was the cause. The role was an opportunity he couldn't turn down, although it left him with too little time to commit to Charmed. From Nip/Tuck's pilot in 2003 until 2005 McMahon juggled both roles, but once it became clear that the Murphy series had serious potential, the character of Cole was soon written out for good in explosive fashion.
Thus, despite Phoebe and Cole having a baby together, the former love interest and likable anti-villain was nonetheless vanquished for good by the Halliwell sisters, leaving his actor free to commit full-time to the role of Nip/Tuck's Dr. Christian Troy. At the time of his exit from Charmed, McMahon claimed in an interview that he was sad to leave the show but excited about the prospect of challenging himself as an actor and booking the next job. The comment could reasonably be read as a very polite way of McMahon saying he was ready for the main role and, as fun as the recurring character of Cole was, the prospect of starring in a show is hard for any actor to resist.