reactionary – "one who does things in response to (because of) what someone else has done, when you do things in response or reaction to other people you are their puppet." FUNKTIONARY
/According to FUNKTIONARY:
reactionary – one who does things in response to (because of) what someone else has done, when you do things in response or reaction to other people you are their puppet. (See: Actionary, Seating, Centroversion & Centering)