A commonly used term in K-Pop lingo is "duality." It refers to the ability of a person, usually an idol, to deliver on contrasting concepts and expressions. An idol's duality is usually brought out on stage during performances, especially when they switch songs. It isn't unusual for performers to take on a whole new persona on stage, but for some, the change is so drastic that it becomes that much more worthy of awe.
NCT's leader and SuperM member Taeyong is probably one of the busiest idols in the industry. However, it is common knowledge among fans that Taeyong is, in fact, an introverted and shy person with a gentle and soft-spoken personality. However, when performing, he commands the stage and the spotlight. It's almost like he's an entirely different person on stage.
SHINee's maknae is playful, goofy, and full of energy even off the stage when he is around his members or friends, but most importantly, he's rather shy and sweet-tempered. However, on stage, Taemin knows exactly how to tear it up. He's fierce and unapologetically intense. The switch is so powerful that it leaves everyone speechless every single time.
SEVENTEEN's sweetest, Jun, is a known ambivert. He's vocal and expressive with his members, which is also a recent development, and usually with his fans too, but otherwise, he's rather reserved. However, anyone who has seen him perform knows for a fact that he's an entirely different person on stage. It is always amazing to see how empowering art can be to someone.
TWICE's Sana is a powerhouse of talent, and while off-stage Sana is a humble sweetheart, on-stage Sana knows that she's the it-girl. The command she has on her expressions is impeccable and effortless and it's a treat to watch her perform.
Anyone who has been on Soyeon's artistic journey with her knows how different Soyeon is on and off stage. As a matter of fact, she's vastly different now than she was a couple of years back, but even then, she's still rather reticent. However, on stage, her performance speaks volumes. There's a reason why she's one of the best female rappers in the history of K-Pop, and the impact her talent has on an audience is amplified by her duality on and off the stage.