  Paradigm shift in gauge topology at finite temperatures, from the instantons
to their constituents -- instanton-dyons -- has recently lead to studies of
their ensembles and very significant advances. Like instantons, they have
fermionic zero modes, and their collectivization at sufficiently high density
explains the {\em chiral symmetry breaking transition}. Unlike instantons,
these objects have electric and magnetic charges. Simulations of the
instanton-dyon ensembles have demonstrated that their back reaction on the
Polyakov line modifies its potential and generates the {\em deconfinement phase
transition}. For the $N_c=2$ gauge theory the transition is second order, for
QCD-like theory with
  $N_c=2$ and two light quark flavors $N_f=2$ both transitions are weak
crossovers at happening at about the same condition. Introduction of
quark-flavor-dependent periodicity phases (imaginary chemical potentials) leads
to drastic changes in both transitions. In particulaly, in the so called
$Z(N_c)-QCD$ model the deconfinement transforms to strong first order
transition, while the chiral condensate does not disappear at all. The talk
will also cover more detailed studies of correlations between the dyons,
effective eta' mass and other screening masses.
