It's been eight years since the 42-year-old actor was first introduced as Elijah Mikaelson in 2010 on The Vampire Diaries. He has since cemented himself at the faithful and forgiving Mikaelson brother who always puts family first.
As The Originals comes to an end with episode 13, "When the Saints Go Marching In," Gillies knows that fans will be left in tears, but hopes they are pleased with how "forever and always" comes to its conclusion.
"It's the end, how can they be happy? I hope they're kind of pleased," Gilles told ET's Katie Krause earlier this month. "The whole premise of the show was [showing] the last days of the Mikaelsons. I hope that they are left with something that slightly fulfills that premise...I think that there are going to be tears."
The tears may come from Klaus' fate (Joseph Morgan). The second to last episode had the hybrid willing to sacrifice himself to save his daughter Hope's life (Danielle Rose Russell). So will fans be shocked by the finale?
"The writers have maintained a level of surprise the entire way through, so I don’t think that there is going to be [shock]," Gilles explained. "I think that we have sufficiently prepared our audience to be sort of gut-punched at any given moment."
One thing that's certain is that fans will definitely miss seeing Gillies as the sophisticated -- but lethal -- vampire who is known for his well-tailored suits. Those suits, at least some of them as he told ET, will remain in the actor's closet. When asked if he stole anything from the set, he slyly replied with a laugh, "Yeah."
"I stole suits. Alright, I confess! CW, leave me alone!" he jokingly revealed. "Here's the deal, [the suits] were cut specifically for my dimensions. Who else was going to wear them? I deserve them, in some way… as a token… as seven or eight tokens."
Gillies had previously told ET that he "prefers to be in suits." "I like them tremendously,” he shared in May, adding that he regularly dresses “like a homeless person” and uses the suits to get into character. “It’s an immediate character transition where you’re getting ready to play the role. You put it on and you suddenly feel like this other animal. It’s unique in that way, I love it. That’s how he’s known."
While fans will say farewell to The Originals on Wednesday, the cast and crew wrapped filming and said their goodbyes back in December. On his last day, Gillies shared an Instagram video of himself and Morgan in costume filming their finale scene ever. The New Zealand native confessed to ET that he was "weirdly shaken" that day and "trembling."
"I was actually trembling in the last scene. It was a strange sensation," he recalled. "I don't think I've ever experienced anything like that before. You know, the only other time I've felt like that was when I married my wife [Rachael Leigh Cook]. So maybe it was a liberating thing."