Citations:bias wrecker

Noun: "(South Korean pop culture fandom slang) a member of a K-pop group with the potential to replace a fan's current favourite member"

 * 2016, "On The Lookout", Campus Life Plus, May 2016, page 22:
 * Be prepared people, they might just be your next idol group bias wrecker.
 * 2019, Adrian Besley, Blackpink: K-Pop's No.1 Girl Group, unnumbered page:
 * Many fans would admit their bias had changed after a particular performance or would refer to a member as a 'bias-wrecker' after they had performed so well or looked so good that they now threatened the top spot of their favourite.
 * 2019, Janet Lira, "Korean Boy Band Gains Worldwide Success", The Advocate (Contra Costa College), 1 May 2019, page A6:
 * However, there are also bias wreckers. That happens when another member of the group begins to steal your attention away and makes you question your initial band favorite.
 * 2019, Saliman Zenati, "Finger Heart Festival", HALLYU Magazine, Autumn 2019, page 7:
 * With the rythmic [sic] and funky sounds of "Feeling" and "Toc Toc", Jeon Sewoon manage [sic] to gain new fans and be the night bias wrecker.