- The Kurgan himself, the Immortal who clawed his way to almost win the Game over a mountain of corpses, and unlike Connor, he sought out other Immortals just to take their heads. His Immortal victims alone likely number in the hundreds, and thats not even counting the countless atrocities he committed against mortals over the millenia. He was such a monster he remains The Dreaded even in the series, years after Connor finally managed to kill him and end his reign of terror. The Kurgan is essentially the absolute worst person to be given Immortality.
- The revelation that Heather MacLeod was raped by the Kurgan. The thought of a sweet, kindly housewife being so brutally assaulted by a deranged Immortal barbarian is enough to make one's skin crawl.
- It was revealed during the Truce Zone when the Kurgan gloats about raping Ramirez' woman and lying that the latter died without dignity, begging for his life. He puts two and two together, realizing Heather was actually Connor's wife, proceeds to gloat more about it, and even has the audacity to suggest she enjoyed it more than any time she had with Connor.
- There's a subtly scary moment when Connor talks to Brenda in the park and during that moment, The Kurgan appears hidden in the shadows doing nothing aside from looking on and disappearing just as quickly. It leads to the moment where he tracks Brenda to her apartment and breaks down the door.
- The Drives Like Crazy scene where he deliberately drives into incoming cars and trucks, causing collisions. And at one moment, he runs over two pedestrians on the sidewalk.
- When he's about to kill Connor, the Kurgan's eyes dilate, almost encompassing his eye giving him an inhuman animal like look.
- In the last Quickening, absolute psychotic animation surround Connor, including incomprehensible beings and demonic looking ones. And unlike the rest of the series, what these entities exactly are, is never fully explained.
- Sometimes things were added in the Watcher Chronicles CD-Rom that created a bit of this in some characters. One example is Michael Moore from "Turnabout". His chronicle says he was taken from an orphanage in the 1830s by a foster family that was cruel and abusive, possibly even sexually abusive. It was so bad his first death was suicide. Imagine having trauma like that and not even being able to escape by dying. Is it any wonder the guy ended up developing a split personality that was a Serial Killer? It's sad he helped a lot of others as a psychiatrist, but couldn't escape his own demons.
- The revelation that Methos repeatedly killed Cassandra just to torture her back in the bronze age.
- Terence Kincaid, the immortal who got marooned on a Deserted Island and ended up starving to death over and over again. It's no wonder he was eager to get back at Duncan when he escaped. Mac hadn't wanted to kill him and never thought he'd end up stranded quite that long. And by extension, any other immortal who endured repeated deaths due to an inability to escape a situation. At least any one buried alive like Nefertiti or Michael Moore would stay dead until they got enough air to wake up again.
- John Garrick, the immortal who ended up psychically tormenting Duncan because unbeknownst to Duncan, he did not escape a Burn the Witch! situation and was burned alive. True that he wouldn't revive until he'd healed enough to facilitate it, but it's still painful to think about.
- There were at least two immortals who ended up trapped in mental hospitals so long that no one remembered who they were or why they were there. One of them tried to get revenge on Duncan by trapping him in an abandoned army base brig for the same amount of time, though he was rescued. That's a bit of a nightmare to imagine.
- The novel "Zealot" expands on Methos comment in Til Death, albeit in a scene cut for time, about a senator, his wife and a slave boy. It ended with Methos being crucified. It's indicated he died a couple times before he was rescued by Constantine. Considering what we know about this form of execution...eesh.
- Kalas, the Big Bad of Season 3, oozes this trope. He kills two or three people each episode he appears in, and at one point abducts his Watcher, straps him to a chair, and electrically tortures him for information. In addition to his crimes, there's also his general demeanor. Most evil immortals tend to be theatrical or entertaining, like Kronos or the Kurgan. Not Kalas. He's icy and humorless, with a simmering rage and sadism hiding just beneath the surface. As if all that weren't enough, he's as skilled as Duncan is. No wonder Mac was so worried whenever Kalas showed up.
- Throughout the series, the question hangs of what might happen should an Immortal break the rule of taking a head on holy ground. In "Little Tin God," Dawson shares an old Watcher legend of the only known time two Immortals fought on holy ground:Joe: It was in Pompeii. 79 A.D.Duncan: The volcano...