Alaric Saltzman finally bested Kai Parker in Legacies and had a few choice words for his brother-in-law's last moments — but why did he say "this is for Jo"? After escaping from the prison world that Bonnie trapped him in in The Vampire Diaries, Kai tried to manipulate Alyssa Chang into destroying that world, taking Alaric, Josie, and Lizzie with it. Josie facilitated their escape as Hope faced off with Kai, then Alaric decapitated Kai, ending a feud that began back on The Vampire Diaries.

It's easy to understand where Alaric's hatred toward Kai originated. Kai and Alaric's deceased wife, Jo, were Gemini twins similar to Josie and Lizzie. But after Jo managed to escape undergoing the merge with Kai, he showed up at Alaric and Jo's wedding and killed his pregnant sister. Before Jo died, the Gemini coven transferred Lizzie and Josie into vampire-turned-birth-mother Caroline Forbes. After the twins were born, Alaric and Caroline raised Josie and Lizzie together, which ultimately led to them opening the Salvatore Boarding School for the Young & Gifted, where Legacies takes place.

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Before being imprisoned, Alaric and Kai faced off, and Alaric appeared to gain the upper hand, using chains to strike Kai down. "That's for my kids," he said with the first strike. "That's for me," with the second. But he only managed to get out, "And this is for —" before Kai thwarted his attack and raised an ax to finish Alaric off. That's when Caroline snapped Kai's neck and finished Alaric's words for him: "For Jo. That's what he was going to say." So, it was fitting Alaric would call back to that fateful conversation from earlier in The Vampire Diaries' timeline and exclaim, "This is for Jo," before taking a sword to Kai's neck. While it may have seemed Alaric said those words because he finally was able to avenge the murder of his wife, his motives weren't about the past but about the future.

Kai Parker of Vampire Diaries and Legacies in his own version of hell

Jo's death haunted Alaric for a very long time, but since then, he'd seen their children grow into teenagers and powerful witches. And despite being long dead, Jo got to see that, too: In Legacies' first season, the necromancer resurrected Lizzie and Josie's biological mother in time for their sixteenth birthday. While their time was short, Alaric got the closure he needed, and Jo told him to thank Caroline for being her daughters' mother. Jo also revealed to Alaric and her siphon Gemini twins, Josie and Lizzie, that she was at peace wherever she was before being resurrected. "I used to watch all of you," Jo said. "Like in a dream where everything is warm and happy." Jo told her loved ones she would be waiting there for them before returning to the afterlife.

In wanting to collapse the prison world, Kai showed no hesitation at the thought of killing his nieces. When Alaric killed Kai, he did it just as much for Josie and Lizzie as for Jo. Jo would have wanted Alaric to do anything to protect their daughters, and as long as Kai was alive, he would be a threat to Josie and Lizzie. Saying "This is for Jo" wasn't about avenging Jo's death. It was about protecting her legacies' futures. With Kai finally dispatched and Jo at peace, Alaric could rest easy again. Granted, he's been through hell and back since and still has Malivore to contend with, but the weight of his past no longer haunts him. Which, in the dangerous world of Legacies, is about the best one could hope for.

NEXT: How Legacies Season 3 Sets Up Caroline's Return (Will It Happen?)