  Coronal rain is the most dramatic cooling phenomenon of the solar corona and
an essential diagnostic tool for the coronal heating properties. A puzzling
feature of the solar corona, besides the heating, is its EUV filamentary
structure and variability. We aim to identify observable features of the TNE-TI
scenario underlying coronal rain at small and large spatial scales, to
understand the role it plays in the solar corona. We use EUV datasets at
unprecedented spatial resolution of ~240 km from EUI/HRIEUV and SPICE of Solar
Orbiter from the spring 2022 perihelion. EUV absorption features produced by
coronal rain are detected at scales as small as 260 km. As the rain falls,
heating and compression is produced immediately downstream, leading to a small
EUV brightening accompanying the fall and producing a "fireball" phenomenon.
Just prior to impact, a flash-like EUV brightening downstream of the rain,
lasting a few minutes is observed for the fastest events. For the first time,
we detect the atmospheric response to the rain's impact on the chromosphere and
consists of upward propagating rebound shocks and flows partly reheating the
loop. The observed widths of the rain clumps are 500 +- 200 km. They exhibit a
broad velocity distribution of 10 - 150 km s^-1, peaking below 50 km s^-1.
Coronal strands of similar widths are observed along the same loops co-spatial
with cool filamentary structure, which we interpret as the CCTR. Matching with
the expected cooling, prior to the rain appearance sequential loop brightenings
are detected in gradually cooler lines from corona to chromospheric
temperatures. Despite the large rain showers, most cannot be detected in AIA
171 in quadrature, indicating that LOS effects play a major role in coronal
rain visibility. Still, AIA 304 and SPICE observations reveal that only a small
fraction of the rain can be captured by HRIEUV.
