  Despite great agreement with experiment, the Standard Model (SM) of particle
physics lacks a viable Dark Matter (DM) candidate and sufficient amount of
CP-violation to account for the observed baryon excess in the universe.
Non-minimal Higgs frameworks are economic extensions of the SM which could
remedy these shortcomings. Within the framework of a three Higgs doublet model,
we introduce an extended dark sector which accommodates both DM and
CP-violation. Such dark sources of CP-violation do not contribute to the
Electric Dipole Moments and are therefore unconstrained. We present a novel
mechanism in which the CP-violating dark particles only interact with the SM
through the gauge bosons, primarily the $Z$ boson. Such $Z$-portal dark CP
violation is realised in the regions of the parameter space where
Higgs-mediated (co)annihilation processes are sub-dominant and have negligible
contributions to the DM relic density. We show that such $Z$-portal CP
violating DM can still thermalise and satisfy all experimental and
observational bounds and discuss the implications of such phenomena for
electroweak baryogenesis.
