Two costumed contestants were revealed at the conclusion of Wednesday's The Masked Singer semi-finals, when The Rabbit was identified as NSYNC singer Joey Fatone and, in a truly shocking outcome, The Lion was also voted off, and revealed to be Rumer Willis.

Willis had commanded the stage with her vocal prowess and magnetic presence during the last eight weeks of the competition, proving time and again how powerful and versatile her singing skills truly are. The Lion's enduring popularity made her elimination all the more surprising.

Willis sat down with ET's Nischelle Turner on Thursday, where she dished on her time on the show, her reasons for signing on to compete and why she choice the amazing Lion costume, which was arguably one of the most impressive costumes of the first season.

"In the beginning, when we had one of the first couple of meetings, they had a bunch of pictures of all the different costumes, and [The Lion] was immediately the first one [I really liked]," she recalled of the regal outfit, dreamed up by Emmy-winning costume designer Marina Toybina. "I just was immediately drawn to that one."

Willis -- who famously got a lion tattoo on her shoulder when she was younger -- said being a Leo played a part in the decision, but it was the power and attitude The Lion costume evoked in her that truly attracted her to it.

"I just [loved] all the gold, and I thought it looked strong and confident," Willis shared. "I love the whole gladiator vibe of all of it."

While Willis rocked the extravagant and luxurious Lion outfit with grace and style, the actress said wearing the incredibly heavy ensemble during the production was physically exhausting.

"It was so heavy, the mask alone was 10 or 12 pounds and that huge big fur cape was probably five or six," she recalled. "By the end of it, I wanted to curl over."

Participating in a reality competition show isn't something new for the 30-year-old performer -- after all, she is a Dancing With the Stars Mirrorball trophy winner after claiming victory with partner Val Chmerkovskiy during season 19.

However, she admitted that the unusual premise for The Masked Singer -- which is an American take on the massively popular South Korean game show King of Mask Singer -- gave her pause.

"I just thought it was a crazy idea," she admitted. "I definitely had to think about it, because I had to think about, 'Is this right for me? Are they going to be able to do it? Obviously, the show worked [in Korea], but how is it going to work over here?'" She explained. "But at the end of the day, I just thought it was a fun opportunity to be able to sing without anyone's prior judgment."

According to Willis, that sort of anonymity while performing is truly "what is so cool" about being a part of the show. "It's just solely based on your talent not based on what people know about you," Willis added.

While she enjoyed getting the chance to see without anyone in the audience knowing who she was, it wasn't long before viewers at home had a pretty good idea that it was Willis behind that elaborate golden mask.

Willis' name was one of the first major guesses Twitter detectives came up with, and that was all the way back near the start of the show. With each week, the clues just piled up and it was almost a lock that she would turn out to be The Lion.

In fact, with a few rare exceptions, Twitter detectives have been right on the money with their predictions each week, as more and more masks come off, and Willis thinks that the show is going to have to get trickier when season two premieres.

"Everyone has been guessing so correctly! I feel like maybe for next season they're going to have to tone down the clues because people got everyone so fast," Willis said, adding that secrecy is also going to get more difficult.

According to the actress, producers were able to keep the contestants' identities secret during the first season because no one knew what the show was going to be like, and it was under everyone's radar. However, with all the attention it's been getting, keeping the masked celebs under wraps is going to be a bigger challenge.

The final three costumed contestants -- The Bee, The Peacock and The Monster -- are still set to face off when The Masked Singer season finale airs Wednesday, Feb. 27 at 9 p.m. ET/PT on Fox.

Check out the video below for a behind-the-scenes look at the show's jaw-dropping costumes and the process behind their development.

RELATED CONTENT:

'The Masked Singer': The Lion and The Rabbit Unmasked in Semi-Finals

'The Masked Singer': Spoilers, Clues and Our Best Predictions -- Updated!

Neil Patrick Harris Swears He's Not The Peacock on 'The Masked Singer' -- So Who Is?