No.
The most famous Russian fighting in Donbas is Alexander Barkashov, the creator and leader of “All-Russian civic patriotic movement Russian National Unity” (RNU). The Russian Nazi RNU is fighting in the Eastern Ukraine on FOR the separatists and AGAINST the Ukrainian army. Putin grew the Russian nationalists [extremists and Russian neo-Nazis] fighting in the Eastern Ukraine on the side of the separatists and against the Ukrainian army.
ADDENDUM RUSSIAN MILITARY NAZIS
Alexei Milchakov from a neo-Nazi St. Petersburg organization “Rusich”. This separatists’ poster presents Milchakov as “The pride and the glory of Russia”. The terrorist group, in which he was fighting in Donbas used to have a Twitter account administered by Milchakov. Another picture, made near Luhansk in September 2014, shows an ear, which was cut off from a Ukrainian soldier. On June 29, 2015, he posted pictures of Ukrainian prisoners of war with mutilated faces.