  In this paper we perform a nonperturbative analysis of a thermal quasifermion
in thermal QCD/QED by studying its self-energy function through the
Dyson-Schwinger equation with the hard-thermal-loop resummed improved ladder
kernel. Our analysis reveals several interesting results, some of which may
force us to change the image of the thermal quasifermion: (1) The thermal mass
of a quasifermion begins to decrease as the coupling gets stronger and finally
disappears in the strong coupling region,(2) the imaginary part of the chiral
invariant mass function (i.e., the decay width of the quasifermion) persists to
have $O(g^2 T \log (1/g))$ behavior. Present results suggest that in the
recently produced strongly coupled quark-gluon-plasma, the thermal mass of a
quasifermion should vanish. We also briefly comment on evidence of the
existence of a massless, or an ultrasoft mode.
