So, when you ask if evil is a positive existent are you asking if death, disease, disaster, etcetera, are entities? Surely you know that some bacteria can invade a living organism and alter its functions (disease) in such a way that it could be destroyed (it dies). And those microorganisms could proliferate in such a way that they could decimate a whole population (disaster). Those microorganisms are, on the other hand, “positive existents”. An besides them, no “death” as a “positive existence” is necessary to explain how a living organism, infested with them, dies.
Would you say that those tiny entities are the Evil? Each one of them? Or a given number (a great number) of them? Or a great number of them, but only if they are together within a reduced space? Or this, but adding the optimal conditions of temperature, pH and other variables, for their proliferation?
And when you suffer some pain, do you tend to think that a chunk of a “Suffering Producer Evil” got stuck somewhere in your body and became one with you, so that you feel it?
Is that your doubt?