Warning! Spoilers ahead for all the mentioned TV shows!Like all genres of TV, fantasy shows aren't immune to incorporating storylines that disrupt the tone and set the series on a bad path. While these plotlines within the shows didn't necessarily ruin or completely derail the overarching narrative, they did make it impossible to consider them truly flawless additions to the genre. There's no reason why a show can't come back from a plot point that alienates viewers and critics. However, this makes it even worse when a series gets lost and can't come back from a significant error in storytelling.

These don't rank among the fantasy TV shows with no bad seasons, as after these storylines were included, things were never quite the same. In some cases, these missteps came at the tail end of the series' run, disrupting the legacy and longevity of the show more than anything. This isn't uncommon, as sticking the landing on a final season of television isn't easy, especially within the fantasy sphere. However, it's almost more upsetting when a series peaks too early and makes a critical mistake in the first or second installments, ensuring the show will always have a mixed reputation.

10 The Vampire Diaries (2009–2017)

Elena's transformation in the later seasons altered the fabric of The Vampire Diaries

The Vampire Diaries is an iconic and beloved supernatural teen drama, but that doesn't mean the show didn't start going off course by the end. The most glaring example of when The Vampire Diaries started losing itself was when Elena was written off the show because Elena Dobrev wanted to leave. However, the seeds of this departure and Elena's troubled characterization were sown throughout the evolution of her sire bond with Damon.

The developing romance between Elena and Damon was a fun and tension-packed part of the first few seasons, but the sire bond changed Elena's character beyond recognition. It also made her feelings for Damon clouded by magic and come off as more of a plot device than a genuine connection between the characters. Elena turning into a vampire was risky, but altering her through the sire bond shifted the emotional core of The Vampire Diaries​​​​​​.

9 Game Of Thrones (2011–2019)

The series didn't do justice to its characters in the final episodes

Game of Thrones is a fantasy TV show with plenty of perfect seasons, but as the series progressed, it began to lose steam. The final season was full of missteps, but the Mad Queen arc permanently changed the way viewers and critics engaged with Game of Thrones. Dany was one of the most compelling and consistent characters in Game of Thrones, and seeing her suddenly change and throw away all her existing morals and values made the conclusion dissatisfying.

It was always going to be difficult for Game of Thrones to weather the last few seasons of the show, considering the fact that George R.R. Martin's book series hasn't progressed past book five. For the most part, Game of Thrones naturally extended the storylines and character arcs, even inventing some unforgettable battles and heart-wrenching moments. However, Daenerys's final moments in Game of Thrones have made it difficult to say that the show is a perfect addition to the fantasy genre.

8 Once Upon A Time (2011–2018)

The fairy tale format of Once Upon a Time wasn't sustainable

Once Upon a Time season 1 is easily the tightest and most dynamic installment of the fantasy show, but that doesn't mean the series isn't worth watching. However, there's a clear shift in quality and tone in season 4 when Anna, Elsa, and the Frozen storyline are introduced. When Once Upon a Time first started, it focused on older fairy tales that were well-established within the cultural conversation. By the time Frozen was included in Once Upon a Time, it felt like the show was grasping at straws.

The fact that the series turned to such a new IP to mine for conflict made it clear that Once Upon a Time was running out of ideas.

The fact that the series turned to such a new IP to mine for conflict made it clear that Once Upon a Time was running out of ideas. Additionally, in the years after, Once Upon a Time rehashed many of the same character relationships and arcs it had already touched upon, with Regina's redemption storyline being one exception. Though Once Upon a Time is a TV show that I miss coming up with theories for, I could never have predicted that what made the show so exciting at first would be its downfall.

7 Lost (2004–2010)

Lost jumped the shark many times throughout its run

Lost was a landmark show on television for many years, carving out a unique niche within the TV landscape and quickly becoming a cultural touchstone. Unfortunately, the premise of Lost wasn't as sustainable as other fantasy series since there's only so far that the survival concept can be taken. To combat becoming boring or repetitive, Lost worked hard to shock the audience every season, but eventually, this grew tiresome, especially when time travel was woven into the story.

The time travel arc in Lost took the show from exciting mystery territory into full outlandish fantasy and changed the tone of the series for the worse. It was difficult to understand how time travel worked and what the rules of the magic system were, and this was largely because the writers of Lost weren't sure of the boundaries of the show's storytelling. This uncertainty carried into the later seasons, eventually defining the controversial final season and panned series finale.

6 True Blood (2008–2014)

True Blood gave too many characters supernatural abilities and identities

There are many aspects of True Blood that hold up well today, from its atmospheric style to the intricate romantic plot lines that keep the audience guessing. The central love triangle between Sookie, Bill, and Eric has stood the test of time, but in the wake of season 3, True Blood started to lose its footing. Season 3 was the height of the show's quality and intrigue, but after discovering Sookie's identity as a fae, True Blood began making all of its characters supernatural.

Part of the fun of True Blood was witnessing the difference between the human and supernatural worlds and witnessing them clash. While it makes sense that there would be pieces of lore that the humans and vampires weren't aware of, after Sookie is confirmed to be Fae, True Blood starts giving everyone an otherworldly identity. There was an element of fun intrigue in not knowing the truth of Sookie's history, and finding out the answers ended up hurting the overall story.

5 The Magicians (2015–2020)

Season 4's tragic loss led to a structural shift in The Magicians

It's largely agreed upon that The Magicians peaked in season 3 with the quest for the seven keys. Though this is the most cohesive arc throughout The Magicians, the series did successfully expand its story beyond the source material by Lev Grossman. However, The Magicians season 5 has lost some of what made the show so special and felt too different from the early installments, largely because of Quentin's death at the end of season 4.

Quentin's death was the saddest scene in The Magicians, and though the series was an ensemble show, Quentin was considered the protagonist. Losing a protagonist is an almost insurmountable change for a TV series, and The Magicians never truly recovered from this loss. Without Quentin, the inherent chemistry and central character dynamic had to shift, and since season 5 turned out to be the final installment, The Magicians didn't have time to carve a new path for the story.

4 Riverdale (2017–2023)

When the fantasy aspect of Riverdale was introduced, it was too much for the story

Paradoxically, Riverdale truly went off the rails when it fully embraced the fantasy elements of the show. Riverdale was always defined by its offbeat premise and outlandish plotlines. However, the introduction of magic, multiple dimensions, and time travel became too much for the series to sustain. Though there had been plenty of mysterious happenings and an atmosphere of the surreal in Riverdale since the beginning, it was the season 5 parallel universe that was the beginning of the end.

Riverdale season 6 introduced explicit witchcraft and magic systems, but the season 5 parallel universe arc hinted at the change coming in the direction of the show.

Riverdale season 6 introduced explicit witchcraft and magic systems, but the season 5 parallel universe arc hinted at the change coming in the direction of the show. It's easy to forget that the writers and creators of Riverdale were creating these narratives with lots of self-awareness, but the tongue-in-cheek layer of the show couldn't balance the wild nature of the fantasy world. While it was still fun to witness the ups and downs of Riverdale​​​​​​, the fantastical aspects changed the nature of the series too much to sustain.

3 The Flash (2014–2023)

The multiverse and overlapping timelines became too much for The Flash to handle

Part of the reason CW's The Flash went on for as long as it did was due to the dedicated fanbase and strong source material. The Flash was one of the most successful series within the Arrowverse TV universe, running for nine seasons and expanding the story to include many fun parts of the science fantasy genre. However, it's largely agreed upon that The Flash started losing steam in season 4, but the problems began with the Flashpoint timeline.

The Flash seasons 1 and 2 had tight, streamlined stories that relied on a central mystery and a set of rules that defined Barry's abilities and those of the meta-human villains. Though it makes sense that Barry would want to go back in time to save his mother emotionally, the fallout of this plotline follows Barry throughout the remaining seasons. Introducing the ability to time travel was a risky move, and season 3 suffers from problems in pacing and character development because Barry creates the Flashpoint timeline.

2 Chilling Adventures Of Sabrina (2018–2020)

The ending of season 1 pushes Sabrina too far into the dark side

The idea behind Chilling Adventures of Sabrina was an exciting blend of the teen, supernatural, and horror genres, but the execution wasn't always perfect throughout the show's run. The series' first season was the best; it intertwined Sabrina's witch side with her attempts to have a normal human life, creating inherent tension and intrigue. However, the series played its hand too soon, having Sabrina commit to the dark side after just one season.

Unfortunately, ever since Sabrina fully embraced the darkness and dived headfirst into her witch side, Chilling Adventures of Sabrina went downhill. The Queen of Hell plotline and her tumultuous relationship with Nick were more confusing than compelling, and it was easy to miss when Sabrina was trying to be a normal teen girl like everyone else. After season 1, it got harder to care about Sabrina's human friends since that aspect of the show was put on the back burner.

1 The Umbrella Academy (2019–2024)

The series' final season cemented the overarching issues of the story

Some of the issues that The Umbrella Academy faced in the later seasons weren't entirely the fault of the series or the writers. The fact that the final season only had six episodes made it difficult for the show to wrap up its many storylines and provide a satisfying conclusion for viewers. There are many reasons why the final season was a misstep, but the relationship between Five and Lila was too much for the series to come back from.

The Umbrella Academy season 4 was set up to fail from the start, but the storyline between Five and Lila made no sense and was a step back for the show. Though they were both technically adults, the romance felt a little uncomfortable, and this wasn't helped by the fact that it came almost out of nowhere. The relationship demonstrates the overall problems with the end of the fantasy series, which was that it was rushed, underdeveloped, and tonally confused.