The Vampire Diaries is at its best when it's morally nebulous, and usually at the center of that prickly milieu is Matt Donovan (Zach Roerig). For eight seasons, our dear Matty Blue Eyes has had the misfortune of being the only responsible adult in Mystic Falls. He's not only had to care for himself, but also for the lives of every living human in town — no pressure or anything.

In tonight's episode of The Vampire Diaries, titled "Who Are You?," Matt once again finds himself at a moral crossroads: Should he help his "friends" (let's not act like Damon and Stefan Salvatore are his best buds) save Stefan's soul, or protect the residents of Mystic Falls from the literal Devil, a.k.a. Cade? For a Good Guy™ like Matt, the choice is obvious.

"Matt is always going to follow his moral compass," Roerig told MTV News ahead of the episode. "He has to make a call for the greater good. He's already saved the town once, so at this point, it's not about Mystic Falls. He's fighting the Devil. It's the kind of situation where everyone, from every side, will actually team up because they can all agree that fighting the Devil is the right thing to do. Even Damon knows that."

So Matt teams up with Dorian and Alaric to try to decipher the Maxwell journal, one very important key to destroying the Devil. Roerig also got the distinct honor of filming his very first (well, only) flashback scene as Matt's ancestor, Ethan Maxwell, the man responsible for making the Maxwell bell (yet another important instrument needed to defeat Cade). "That was a very fun way to end the season out," Roerig said. "I didn't know it was going to happen until we shot it. We tried on a lot of wigs, but they ultimately went with my hair."

As for Matt and Damon's rocky rapport, expect their newly minted understanding to be tested by Stefan's attempt to destroy Mystic Falls. Now Damon wants to trade the Maxwell journal to Cade in exchange for Stefan's soul. Yeah, that's not going to fly with Matt, who's been over all of this supernatural stuff, particularly the Salvatore brothers, since day one.

"I don't know if he prefers either of them," the actor said when asked which Salvatore has a better standing with Matt. "I think Matt would take them or leave them. He takes them because he kind of has to. He's had more of a camaraderie with Damon in certain instances. I don't know if he's over the whole Penny thing with Stefan, so I guess Damon has the upper hand."

But that doesn't mean he's going to let Damon get his hands on the Maxwell journal. After all, only a Maxwell heir can ring the bell and defeat Cade, so Damon's going to need to work with Matt if he wants to break Cade's eternal bond. Although, according to Roerig, there's a "slight twist" in the series finale that changes Matt's role in the Devil's potential destruction.

Looking back on the show's eight seasons and how much Matt has grown since the pilot, it would be easy to highlight Matt's more heroic moments, like that time he jumped in the pool, intent on killing himself, so he could reunite with his sister Vicki on the Other Side. Or that time he saved Jeremy's life, only to practically die in the aftermath. Or any of the other countless times he should have died. But for Roerig, it's Matt's quieter, more human moments that will stick with him.

"Matt always felt displaced in Mystic Falls, so having his father return was a big moment for him," he said. "Not only that, but to also find out that he had so much history in this town. It was really moving. It's nice to see Matt go through something that didn't have to deal with anyone else. It was just a raw, human story."

"That's why one of the most memorable moments on the show, for me, was Sheriff Forbes's death," he concluded. "There wasn't anything supernatural about it. She died, and that was it."

While Roerig would neither confirm nor deny the possibility of more death in the big series finale, he did tease the return of some beloved characters. "It's been so crazy just seeing some faces that we haven't seen in a long time on the show, or for me, personally, coming back for the finale," he said. "It's a really special episode."