Putin is hungry for power. He wants to control more territory and was hoping that Trump would not challenge anything he does. The problem for Putin is that Trump can't control everything America does because Congress won't let him.
I don't doubt that Putin is a slimeball, but it seems to me that he and Russia are at this point in history the primary force of decency in the world. Fighting the CIA, Mossad, and Saudi mercenaries, showing some care for the Russian people when it comes to NGOs, GMOs and other globalist projects, etc.
Probably it is just an accident of fate that doing the effective and resistant thing happens to be doing the right thing at this point. A reflection of the absolute 'evil' (or whatever one wants to call it) of the Western deep-state domination and the Chinese Communist Party's deals with them.
Or it's all just Putin just acting his part in the global stagecraft. Hard to tell.