The Vampire Diaries Universe encompasses three shows, and they have several connecting storylines and characters on top of a shared world that link the shows together. However, for as many of the characters may have interacted, there were still a handful of character interactions that never occurred on-screen but should have. For example, while the Mikaelson siblings terrorized Mystic Falls for a while, no one from Mystic Falls met Freya other than Stefan during his brief trip to New Orleans. Plenty of opportunities for character collaboration were made more difficult, given the number of fan favorites that died throughout The Vampire Diaries and The Originals​​​​​​.

Legacies missed an opportunity during Kai's return to have him interact with Lizzie. Caroline only returns to Legacies after Josie has left. The Vampire Diaries, The Originals, and Legacies all feature characters who are similar to each other but never get the chance to meet. Had they, maybe they could have helped or learned from each other. In other circumstances, seeing certain characters in the same room could have been a highly amusing and entertaining opportunity that the franchise never took advantage of. For example, Bonnie Bennett and Freya Mikaelson were both highly powerful witches but never worked together or against each other. As a younger Ripper, could MG help show Stefan another side of control he had never mastered?

Related: The Originals: Main Characters Ranked By Tragedy

8 Klaus And Kai

The Originals Klaus Mikaelson and The Vampire Diaries Kai Parker
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Somehow, The Vampire Diaries succeeded in creating an even more chaotic villain than Klaus with Kai. With no family loyalty, Kai is not grounded or held accountable by anyone for his heinous actions. Klaus and Kai would have been a fascinating and very entertaining collaboration. Kai can be just as manic as Klaus but hones a charisma and sense of humor that could drive even Klaus mad by Kai's willingness to harm anyone, including his unborn and later child nieces. With as many issues as he has with his family, Klaus always wishes to protect his siblings rather than kill them. Watching the Original Hybrid face-off against the younger Heretic would have been an incredible sight, one that could have been even more complex and intriguing had they been forced to team up.

7 Stefan And MG

Vampire Diaries Stefan and Legacies MG
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Throughout Legacies, MG has shown more control than Stefan was gifted throughout The Vampire Diaries. Other than the brief instance MG truly lets loose, he tended to get himself back on track relatively quickly. MG never experiences the constant back-and-forth extremes that Stefan suffered, as that part of the human blood addiction was never a forefront storyline for MG. While Stefan taught Caroline to control herself, she quickly surpassed Stefan as a master of control as he continued to struggle when given access to human blood. While Stefan could act as someone with decades of experience and guilt to show MG why staying away from human blood is a better alternative for them, MG may have been able to help Stefan through his human blood struggles in a way others could not have understood.

Related: Legacies: Characters Whose Story Arcs Failed Them

6 Hayley And Jed

The Originals Hayley and Legacies Jed
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Being an Alpha can be a massive responsibility, and Hayley, with Jackson's help, learned how to gain the respect and control of the Pack. Hayley became beloved by the werewolves by her willingness to fight for and help them. It was something that also meant a lot to Jed. At the beginning of Legacies, Jed could have used Hayley's guidance toward what it took to welcome a new werewolf to the Pack when Rafael initially joined the school. However, over time, it grew clear how much the Pack at the Salvatore School and being Alpha meant to Jed. Hayley understood the trials of trying to gain the trust and loyalty of a Pack, and perhaps she would have been an excellent person to speak to about it.

5 Bonnie And Freya

The Vampire Diaries Bonnie and The Originals Freya
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How did such two powerful witches never get to be together on-screen? Bonnie is still learning her capabilities and the range of her power throughout The Vampire Diaries. However, Freya is well aware of her skill set and holds centuries of intelligence in magic. So it was already dangerous to mess with either of them individually. However, as a duo, they would have been a force to be reckoned with beyond any other combination of witches. Bonnie and Freya helping and learning from each other, whether they were allies or enemies, could have been an intriguing way to match the two witches up. Maybe Bonnie could have found solutions to things in the Bennett family's grimoires to help defeat the Hollow that Freya had not been able to find in her family's grimoires or her own experience.

4 Tyler And Jackson

Vampire Diaries Tyler and The Originals Jackson
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Where Tyler fought his werewolf side, Jackson embraced it. Tyler never had a teacher to help him understand what it means to be a werewolf. Mason died too early, and while Caroline was a solid partner in discovering what it means to be supernatural, being a vampire dealt with a different set of conflicts than being a werewolf. Jules was a part of helping Tyler through it. Still, that relationship was never heavily explored, other than Jules' pack interest in using Elena to break the Sun and the Moon curse and kidnapping Caroline.

However, Jackson was an Alpha. He welcomed the good and the bad of being a werewolf and found pride in his Pack, his position, and his relationship with Hayley. While Tyler's actions against Hayley may have resulted in the two having a more antagonistic relationship, had things gone differently when Tyler went searching to understand his identity, Jackson would have been a solid person to help him through it, had his Pack not been cursed at the time.

3 Katherine And Kol

The Vampire Diaries Kol and The Vampire Diaries Katherine
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Of the Mikaelson siblings, Kol never got the opportunity to share screen time with Katherine, which was unfortunate given their many similarities. Both exhibited selfish behavior, given their desire to avoid being killed or daggered by Klaus. However, Katherine and Kol each had plenty of charisma and, occasionally, showed enough motive to be an intriguing team had they been willing to go against Klaus together.

Katherine had the opportunity to portray her antagonistic relationships with Klaus and Rebekah and her on-and-off romance with Elijah. However, having her collaborate with Kol, who always felt left out of Always and Forever, could have been intriguing from the standpoint of a curious mix of danger, and if this is a duo who would betray each other or find an unexpected bond had they been given a chance.

2 Caroline And Josie

Vampire Diaries Caroline and Legacies Josie
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Caroline interacts with a childhood Josie in The Vampire Diaries and a young teenage Josie in The Originals. But, in Legacies, all of Josie and Caroline's interactions are over the phone or off-screen. Caroline is searching for a way to stop the Merge, and it is never shown on screen how Caroline could help Josie in person through all she had experienced. It would have been exciting to see Caroline interact with both of her daughters. Luckily, fans were treated to Caroline's reunion with Lizzie in the Legacies series finale.

1 Lizzie And Kai

Legacies Lizzie and Legacies Kai
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While Kai may have gotten near a young Lizzie in The Vampire Diaries, his return on Legacies has him mainly spending time with Josie. While Kai's interactions with Josie do plenty of exciting things for both characters and the show, it also would have been interesting to see Lizzie's reaction and potential banter with Kai. Instead, Lizzie was given more charismatic and comical dialogue of the twins, which had a better chance of standing banter with Kai's quick comebacks. When Jo briefly returned from the dead, Josie featured more heavily in that story. Although Kai was severely dangerous, Legacies should have taken the opportunity to allow both the twins to face off against Kai, as he is a part of their coven, biological family, and history.