Pre debut busking days covering BTS, EXO, Big Bang, NCT, Seventeen, etc. A.C.E killed EVERYTHING! Their dance skills are no joke, but their vocals are on point as well. They remain underrated in Korea, but have a large growing international fanbase. You should check out their cover of Youngblood. It really shows off their vocals.
if you like ROCK music you should react to Royal Pirates - Disappear MV / Dangerous MV / Run Away MV / Drawing The Line MV / Shout Out MV c: (there's a few versions of some of these too, also they're korean american. a very tragic band too. very unlucky, but hardworking, and tough/strong) ^^