I really recommend that you just watch most of Patrick Lancaster's reporting from before the war even started. He covered most of this stuff in detail, most of which never reached official press on either side. It depends on if you trust his translation and if he is getting honest interviews (which imo he is and he is, as even now most people generally have mixed feelings on both the Ukrainian and Russian military, and mostly want tbe fighting to stop, with their only real difference being that when Russia comes in they usually bring food and water, but most universally condemn the neo-Nazi groups that were there previously). It's a lot of shit, no one article, which is why it is difficult to convey.

As far as I can tell the 'ethnic cleansing' hadn't actually started in earnest, mostly due to the efforts of the DLR and DPR. What had happened at that point was the outlawing of teaching Russian language in schools (a direct violation of the minority rights that had been formally guaranteed by the Constitution), the killing of open leftist political members who demonstrated, and roving gangs of neo-Nazis outside of places like Mariupol who were known to beat, rape, or murder people after dark regardless of ethnicity.

That being said, large sections of these neo-nazi and none neo-nazi groups definitely talked about 'cleaning' the Donbas on a regular basis, though what exactly they meant by that was always cagey. However, from what we can see from towns that have been 'liberated' from Russian control, this basically means killing or jailing anyone suspected of being Russian collaborators, which would have meant most of the DNR and LNR, basically every military aged male.