I don't see Satan as a separate entity, as God is in complete control - but when we misuse our free will to rebel against His will, we become "little satans". But still under His supreme jurisdiction, since "as we sow, we reap" - no escaping universal justice, of which He is the author.
God chose to describe satan as an entity able to exercise enough free will as to rebel.
We may not know quite what all that means. But I still prefer to construe things as The Father construes them.