On the January 6 episode of the MBC singing competition 'Mask King,' contestants battled for a chance to overthrow the latest king 'Eagle'!

During one battle, contestants 'Kongjwi and Patjwi' and 'A Good Brother' performed a duet for the audience, singing G.NA and Rain's "What I Want To Do When I Have A Lover." The audience vote revealed that 'A Good Brother' beat 'Kongjwi and Patjwi,' meaning 'Kongjwi and Patjwi' had to drop out of the competition and reveal her identity. 

'Kongjwi and Patjwi' proved to be none other than Lovelyz's Ryu Soo Jung, who immediately went into a jazz-inspired cover of Red Velvet's "Bad Boy." During the performance, the panel was wowed by her unique vocal talent as well as her strong visuals.

The short clip that told the audience a little bit about her background also pointed out that she was known to have a remarkably large appetite.

"I really, really like food as it is a source of energy for me. I think it would be great if Lovelyz's music can be like that [for other people] too," she began. 

"My family likes this program, but I didn't let them know that I was going to appear on it," she confessed with a smile. "This was really special. It was a great stage."

Check out Ryu Soo Jung's full reveal stage below!