convert; person who changes allegiance or belief
Refers to someone who has changed their ideological, political, or religious stance, often with a connotation of switching sides or abandoning a previous position.
He became a convert from a former opponent.
That politician is known as a turncoat.
Compound of 転向 (conversion, change of direction) and 者 (person). The exact historical derivation is uncertain, but the term is conventionally associated with ideological or political reorientation.