Hella Chluy- Derives from the Cambodian word "Chluy" Which means being Sheisty, Shady, Rude, etc. It has always been in the common Cambodian-American vocabulary but popularized by Memo Jackson (Chluy Films) Best used as a replacement to WTF towards someone. Usually used at the funniest moments!
In BTS song Mic Drop ft. Desiigner, the English part says "Did you see my bag? Do you see my bag? It's hella trophies and it's hella thick". They are referring that since they work hard their bag contain lots of trophies and it's heavy (thick). Since the original version is in Korean, when they sang that part in English it was funny so many people made it into a inside joke.