Russia has no interest in annexing Western Ukraine. But at the very least it wants autonomy or independence for the country’s Russian-speaking east and south - with a special guardian reserved there for Moscow.
That’s almost the wrong question. It isn’t want does Russia want. I think the question is what does the EU want to try to grab? The answer is the Europe will only be happy if they can expand into all of Ukraine, culturally Russian parts at all. They want Ukraine in NATO, 200 miles from Moscow and Volgograd (Stalingrad). And would happily want to take over the Navy base at Sevastopol.
The EU and NATO has turned into a pure menace to world peace. Libya, Syria, and now they are spoiling for expansion in the east. And when Putin opposes them even rhetorically, he becomes the vicious aggressor.
The model is always agree with Europe, or be the aggressor. Or in the case of America, be selfish and uncaring. But either way, all must bow to Europe. Its sickening to watch the Eurothugs do their work.