Did/does the Ukraine use the T-84 in the Donbass conflict? I know they didn't use the Oplot, but wasn't sure about the straight T-84. Or have all the T-84s been retired or upgraded?

Hope it helps:
(...) in a 2015 statement by Sergey Pinkas, the deputy general director of Ukraine Defense Manufacturing, he explained that the reasoning behind the Oplots sale to Thailand is financial: each Oplot sells for $5 million dollars, money which could then be used to upgrade ten T-64 tanks to the more effective BULAT standard.