The midseason premiere and 100th episode of “The Vampire Diaries” was absolutely amazing! However the ending left me with a slight case of déjà vu – and “Buffy the Vampire Slayer” fans will know what I’m talking about.

WARNING: SPOILERS AHEAD. Do NOT continue reading if you have not watched the 100th episode of "The Vampire Diaries."

Episode 11, “500 Years of Solitude,” mainly focused on Katherine on her death bed. The former vampire appeared to have given up and accepted her impending demise of old age, but in the final moments of the midseason premiere decided that she wasn’t ready to let go. Working with her diabolical daughter, Nadia, Katherine decided that she wanted Elena’s young vampire body … and used a traveler spell to become a passenger in her doppelganger.

It was a shocking an unexpected moment all around – however former “Buffy the Vampire Slayer” viewers have been down that road before.

Not familiar with the fabulousness that is “Buffy”? Let me explain:

In episode 15 of season 4 Buffy came face-to-face with her former friend and fellow slayer, Faith. While the two used to be partners and working for the Watcher’s Council, Faith decided to use her powers for evil and began working for the Mayor. The Mayor had plans on killing everyone at the Sunnydale High School graduation with Faith at his side; however a fight between Faith and Buffy left Faith in a coma before the Mayor’s big day.

Buffy ended up defeating the Mayor with the same knife she used to stab Faith … and Faith reawakened from her coma eight months later to seek revenge. The Mayor may have died, but he left Faith with a mysterious and magical gift, a Draconian Katra device … the gift that would allow her to switch bodies with someone. Episode 15 ended with Faith and Buffy engaged in a brutal fight and Faith whipping out her gift to trade bodies with her nemesis.

“The Vampire Diaries” put a slight twist on their story by (seemingly) not having Elena and Katherine switch bodies -- but instead having Katherine “share” Elena’s body with her. However a promo video for episode 12 makes it appear as if Katherine wants Elena out of the body, and the synopsis teases that Elena will find herself in a “life-threatening situation with only minutes to figure out how to save herself.”

So, what will happen next with Katherine, Elena and the gang? We have three theories based off of “Buffy the Vampire Slayer”:

1. Bullying

 In season 4, episode 16 of “Buffy,” Willow is introducing Buffy to her friend Tara for the first time. But Faith (as Buffy) quickly realizes that Tara and Willow are more than just friends and has some “ruthless fun” at their expense.

One possible idea for episode 12 of “The Vampire Diaries” is for Caroline to confess to Elena (really Katherine) that she had sex with Klaus. Since Katherine loves to ruin people’s lives (and the fact that Caroline hooking up with Klaus is HUGE gossip), the theory is that she’ll reveal Caroline’s steamy woods session with the whole gang. And we can imagine a nasty fight since Caroline’s ex, Tyler, back in town.

2. Steamy Hookup

Vampire Diaries We can totally see Katherine breaking Damon's heart all over again. Photo: CW

Faith (as Buffy) pays a visit to Buffy’s boyfriend, Riley. Not realizing that Faith took over Buffy’s body, the two have sex. We could totally see “The Vampire Diaries” taking a similar route by having Katherine (as Elena) completely blow off an apologetic Damon and try and hook up with Stefan.

3. Becoming A Hero

Vampire Diaries Could Enzo play a role in the Katherine/ Elena drama in episode 12? Photo: CW

Faith had plans to leave town with Buffy’s body. However news about a vampire attack in a church forced her to postpone her plans to help the innocent. That decision ultimately lead to Faith and Buffy reuniting and fighting to get control over the bodies. With the help of Willow and Tara, Buffy (in Faith’s body) was able to use her own magical devise to reverse the spell by the Drocanian Katra.

The promo for episode 12 makes it seem as if Katherine (in Elena’s body) wants to skip town. However, something is going to keep her in Mystic Falls. It could have something to do with the fact that Nadia and Katherine need/want Katherine’s old body and the Salvatore’s won’t hand it over. Or it could have something to do with the return of Enzo and the “acts of revenge” that he wants Damon to help with. Will Katherine try to save the day because it’s the Elena thing to do? Doesn’t seem likely … but who knows!

What do you think will happen in the Elena/ Katherine saga? Do you think it’s similar to “Buffy the Vampire Slayer”? Let us know in the comments section or send a tweet to @AmandaTVScoop.