In "A Lying Witch and a Warden", Luz laments not being able to pull a lever because of her weak nerd arms. Come "Wing It Like Witches", she's able to bridal carry Amity without breaking a sweat.
And in "Watching and Dreaming" those same weak nerd arms are able to pull Belos out of the Titan's heart.
Amity angrily demanding to know who and what Luz is while throttling her in "I Was a Teenage Abomination" becomes even funnier later on when it turns out that a valid answer to that question is "your future girlfriend."
In "Lost in Language", Amity comments in an annoyed tone how she and Luz are going to be "stuck together forever" while Otabin is sewing them into his book, something that will be a dream come true for her in just a few weeks' time.
In "The Intruder", Luz excitedly calls King a prince, before he reminds her that he's a king. Come "Echoes of the Past", and we learn that Luz was technically correct.
Adding to that, King is established as a Badass Adorable and Eda's battle partner when they have to face the Warden. He won't back down even when his opponent is much larger and stronger. It makes it all the more awesome when we learn that King is literally a child, implied to be even younger than Luz since he hatched eight years before Luz came to the Boiling Isles. King may not be a king of demons, but he is definitely stronger than he looks.
In the beginning of "Covention", Luz is reading a passage from The Good Witch Azura where the sky is compared to cotton candy of all things. This also happens to be the first episode that focuses on Luz's relationship with Amity, and cotton candy is the color that Luz uses to describe Amity's hair dye in the episode where they start dating.
In "Once Upon a Swap", King's mind ends up in Luz's body. It wouldn't be the last time that Luz is inhabited by a Titan.
"Through the Looking Glass Ruins" had one of the suggested search results when Luz is looking up information on humans is "hunting basilisks", meaning that after Vee and the others escaped someone from the Emperor's Coven resorted to Googling how to find them.
After Season 1, easily the most popular portrayal of the Lumity romance was for Luz to be ridiculously Oblivious to Love despite Amity's best efforts. Let's just say Season 2 didn't go that direction.
The Luz Clawthorne fic series has shown a few things that were later surprisingly proven correct in Season 2:
In "Chapter 9: I Ain't Troubled Yet!", Luz questions Principal Bump if his head demon, Frewin, is supposed to act as glasses and help him see. "Hunting Palismen" actually reveals that Frewin really does help him see, as he has no left eye.
In "Chapter 52: No Dancing Around", Amity decides to become a wild witch due to not wanting to join the Emperor's Coven (which was Odalia's dream for her) after shaking off all of her mother's influence. 2 weeks later, "Reaching Out" aired and she's come to the same decision in the show.
Speaking of "Them's the Breaks, Kid", both works reveals Willow's father, Gilbert, studied in the construction track when he was a student; however since the episode aired before Willow's fathers were properly named, in the show Gilbert's the Korean based father while in the fic, he's the African-American based one.
Hooty demonstrates early on that he has a Lockdown mode for security reasons, a fact that gets unintentionally confirmed in "Hollow Mind".
Another example in "Hollow Mind" is the reveal that Hunter was a coven scout before he became the Golden Guard, a fact that was shown in "Chapter 55: Deserve Nothing".
"Chapter 12: Heart to Heart" shows that Willow's dads taught her a technique for panic attacks, which she canonically demonstrates in "Labyrinth Runners".
"Chapter 56: Going Through Changes" has Kikimora getting demoted for her recent actions involving acting behind the Emperor's back, something that comes to pass in "Clouds on the Horizon".
While King reminds Amity that she started out trying to get her future girlfriend dissected, remember that the first thing Luz did in Amity's direction was blowing a raspberry because her first impression was her future girlfriend bullying Willow.
All of the interpretations of Odalia being the worse and more abusive of the Blight parents while Alador is portrayed as being less harsh and just trying his best while also trying to appease his wife in fanworks back in Season 1 becomes very much vindicated once Season 2 airs and it's revealed throughout how horrible Odalia is with her treatment of Amity and her approval of Belos's genocidal plans. While Alador on the other hand, is shown to actually care for his kids and resolves to be a better father to them while also pulling a Heel–Face Turn in "Clouds On The Horizon", by helping the gang with stopping the Day of Unity.
It was popular to depict Emperor Belos and King Andrias meeting, due to their apparently similar goals of using an artifact stolen from the main hero to conquer another universe. Both shows eventually revealed that the two actually couldn't be any more different, as Andrias is a Tragic Villain and pawn to a Greater-Scope Villain who ends his series as The Atoner, while Belos is a racist genocidal witch hunter who is fully in control of his own decisions with no outside influence, and was lying about his goal to "unite the realms" (and never planned to conquer Earth). If anything, Andrias has more in common with Hunter due to his past, while Belos is more like Andrias' father and abuser, Aldrich.
"For the Future" reveals that Boscha deeply misses Amity and wants to be friends again, though in an unhealthy and obsessive way. This has been depicted in many a fanwork, namely The Raven & the Owlet.
A meta example: A total solar eclipse took place across North America on April 8th, 2024, a full year after the series aired its final episode "Watching and Dreaming".
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