빌런 /bil-leon/
Villain / Chaotic person
From English 'villain' — describes someone acting strangely, annoyingly, or outrageously in real life. Not necessarily evil, just disruptive or bizarre.
Examples
지하철에서 빌런 만났어
I ran into a total villain on the subway
우리 팀에 빌런 있어
There's a chaotic troublemaker on our team