  Relic galaxies are massive, compact, quiescent objects observed in the local
Universe that have not experienced any significant interaction episodes or
merger events since about $z = 2$, remaining relatively unaltered since their
formation. On the other hand, massive and compact Early Type Galaxies (cETGs)
in the local Universe appear to show similar properties to Relic galaxies,
despite having substantial accretion history. Relic galaxies, with frozen
history, can provide important clues about the intrinsic processes related to
the evolutionary pathways of ETGs and the role that mergers play in their
evolution. Using the high-resolution cosmological simulation TNG50-1 from the
Illustris Project, we investigate the assembly history of a sample of massive,
compact, old, and quiescent subhalos split by satellite accretion fraction. We
compare the evolutionary pathways at three cosmic epochs: $z = 2$, $z = 1.5$,
and $z = 0$, using the orbital decomposition numerical method to investigate
the stellar dynamics of each galactic kinematical component and their
environmental correlations. Our results point to a steady pathway across time
that is not strongly dependent on the environment. Relics and cETGs do not show
a clear preference for high or low-density environments within the volume
explored at TNG50. However, progenitors of Relic galaxies are shown to be
located in high density since $z = 2$. The merger history can be recovered from
the hot inner stellar halo imprints in the local Universe. In the current
scenario, the mergers that drive the growth of cETGs do not give rise to a new
and distinct evolutionary pathway when compared to Relics. This is despite the
reported effects on the age and metallicity of the kinematic components.
