Russians have conducted a military operation of much greater scale in Ukraine than in Syria. Bigger than any other in Russian history since World War 2.
Russians have used hundreds of cruise missiles and ballistic missiles in to strike at high value targets across Ukraine (1900 in total). This is in addition to using aircraft to strike at other targets across the country on a regular basis and heavy artillery to shell locations of resistance.
The war is as brutal is it can be.
Yes, nuclear weapons are left.
Russian forces lost the battle for Kyiv in the 1st phase of war. Now the focus is on the East to annex Donbas but Ukranians will continue to resist in this region as well.
Fact of the matter is that Russians have historically struggled to fight in European locations. Broader perspective in following post:
Post in thread 'US Army plans for the Precision Strike Missile'
https://defence.pk/pdf/threads/us-army-plans-for-the-precision-strike-missile.740834/post-13734069