No, it can’t. There are so many kinds of evil in so many different contexts, that you can’t compare one to another.
I see evil on two levels – let’s call them macro-evil and micro-evil.
Micro-evil is when a person does something bad but on a small level – a parent molesting a child, a kidnapper killing his victim, and so on.
Macro-evil is on a larger scale – nation, large group of people, etc. The Armenian Genocide was a macro-evil. The Holocaust was a macro-evil. Slavery was a macro-evil. Brainwashing is a macro-evil.
But even then, how do you compare? Was the Armenian Genocide by Turkey worse than the Holocaust? Where do the massacres in Serbia rank? And what about the genocides in Sudan and Rwanda?
I just don’t see how you apply rankings or degrees.