Tera-Leptons Shadows over Sinister Universe
  The role of Sinister Heavy Fermions in recent Glashow's SU(3)*SU(2)*SU(2)'*U(1) model is to offer in a unique frame relic Helium-like products (an ingenious candidate to the dark matter puzzle), a solution to the See-Saw mechanism for light neutrino masses as well as to strong CP violation problem in QCD. The Sinister model requires a three additional families of leptons and quarks, but only the lightest of them Heavy U-quark and E-"electron" are stable. Final neutral Helium-like UUUEE state is an ideal evanescent dark-matter candidate. However it is reached by multi-body interactions along a tail of more manifest secondary frozen blocks. They should be now here polluting the surrounding matter. Moreover, in opposition to effective pair quark annihilations, there is no such an early or late tera-lepton pairs suppressions, because:a) electromagnetic interactions are "weaker" than nuclear ones and b) helium ion 4He++ is able to attract and capture, E-, fixing it into a hybrid tera helium "ion" trap. This leads to a pile up of relic (4HeE)+ traces, a lethal compound for any Sinister Universe. This capture leaves no Tera-Lepton frozen in Ep relic (otherwise an ideal catalyzer to achieve effective late E+E- annihilations possibly saving the model). The (4HeE)+ Coulomb screening is also avoiding the synthesis of the desired UUUEE hidden dark matter gas. The e(4HeE)+ behave chemically like an anomalous hydrogen isotope.Also tera-positronium (eE+) relics are over-abundant and they behave like an anomalous hydrogen atom: these gases do not fit by many orders of magnitude known severe bounds on hydrogen anomalous isotope, making grave shadows over a Sinister Universe. However a surprising and resolver role for Tera-Pions in UHECR astrophysics has been revealed. 
D. Fargion, M. Khlopov