When millions are eager to exterminate each other, they could not be all white and fluffy.
They used to describe Civil war's events as "Брат шёл на брата"
Huge rate of atrocities happened, no doubt.
As usual, western states ("partners", how Putin calls them now) could not resist to not participate. Otherwise... we would live now in an absolutely different world.
This might be of interest for you https://en.wikipedia.org/wiki/Russian_Civil_War