So in your mind Zelensky is killing those people. Not the invading army?

Yes, obviously. If he did not kidnap people off the streets (after forbidding people to leave the country so that there is more cannon fodder) and forcibly sent to the frontlines, those people would be alive, wouldn't they?

The "invading army" also killed many people of course (the civilians who got hit by rockets/drones) so of course the war should be finished as soon as possible (but this is not in Zelensky's interest because he will lose power and all those billions of dollars), but the number is just incomparable to the amount of people Zelensky has killed and terrorized (and continues to kill and terrorize).

And you did not provide sources to claim that Zelensky is a "sadistic mass murderer" You provided two separate incidents that are being investigated.

So, forbidding millions of people to leave the country so that they can be kidnapped off a street and then sent to die does not fit your definition of "sadistic mass murderer"?
Well, then I can only wish you to one day have such a glorious leader in your country as well, that will do to you and your family the same absolutely not horrific things that you support him doing to Ukrainians.