Complexion rhymes with:
circumspection, inspection, introspection, reinspection, advection, affection, circumspection, collection, confection, connection, convection, correction, defection, detection, direction, disaffection, disconnection, disinfection, dissection, ejection, election, erection, flexion, imperfection, infection, inflection, injection, inspection, insurrection, interconnection, interjection, intersection, introspection, objection, overprotection, perfection, predilection, preelection, projection, protection, recollection, redirection, reelection, reflection, reinspection, rejection, resurrection, section, selection
Complexion sounds like:
cannibalism, compulsion, convulsion