1 of 2 things will happen,

1.) Ukraine will probably sue for peace and cede territory just like Finland did in 1940, but Putin will probably declare victory and the war will end pretty much (except for the flame wars on the internet)

2.) Russia will launch everything they have at Ukraine and declare a full-scale war. From here, we can assume 2 more scenarios:

Russian victory: somehow, by some fucking miracle from Buddha himself, Russia will win the war. They'll probably set up a puppet regime, annex territories east of the Dnieper, or hell, they'll probably annex all of Ukraine. Then they'll make damn sure NATO stays off their fragile asses.

Ukrainian victory: either ends like 1.) or Ukraine will remain the same but staunchly more neutral and less neo-liberal than before.

Nobody knows what'll happen when the rapidly approaching victory day deadline arrives. All we know is that Russia is standing on its knees and Putin will probably whine like a toddler because teddy won't move.