Genesis 3:1-5 Now the serpent was more crafty than any of the wild animals the LORD God had made. He said to the woman, “Did God really say, ‘You must not eat from any tree in the garden’?”
The woman said to the serpent, “We may eat fruit from the trees in the garden, 3 but God did say, ‘You must not eat fruit from the tree that is in the middle of the garden, and you must not touch it, or you will die.’ ”
“You will not certainly die,” the serpent said to the woman. “For God knows that when you eat from it your eyes will be opened, and you will be like God, knowing good and evil.”
Genesis 3:13-14a Then the LORD God said to the woman, “What is this you have done?”
The woman said, “The serpent deceived me, and I ate.”
So the LORD God said to the serpent, “Because you have done this ...
God ruled against the serpent, finding him culpable in the sin of Adam and Eve.
Romans 5:12 Therefore, just as sin entered the world through one man, and death through sin, and in this way death came to all people, because all sinned—
The death of all human being, our mortality, is a direct result of the actions of the serpent in the garden.
Revelation 12:9 The great dragon was hurled down—that ancient serpent called the devil, or Satan, who leads the whole world astray. He was hurled to the earth, and his angels with him.
Makes clearer the identity of the serpent in the Garden of Eden.
Thus the mortality of all mankind and the death of every human being who has ever lived can be laid at the feet of Satan.
Even the death of Enoch, who did not die, can be blamed on Satan since Enoch would have died and was dying as are all living things, due to Satan's deception to Eve.
Even those killed by God, would have died of natural or unnatural causes eventually because of Satan's deception.
Thus Satan murdered EVERYONE.
I agree with the consensus of opinion, there really is no comparison between the body count of Satan and God.