Putin will kill as much as he deems absolutely necessary.
There are a lot of rich, unscrupulous Russians that are very upset with Western politicians. They have means and motive.
One only has to look at pictures of Grozny or some Syrian cities to see how far Putin will go and how much damage Russian military might can do.
You only have to look at Baghdad or Fallujah or some Syrian cities to see how far an unnamed super power will go and how much damage the unnamed super power can do. And about those rich, unscrupulous oligarchs of that other super power’s capital. It appears Russia thinks like you do.