The word "satan" means "adversary." It is not a name. It is preceded by an article, "the adversary." Articles do not usually come before proper names when they are the subject of a sentence. they are used before non-Greek names to indicate their form when not subjects. The translators, however, wanted to reinforce their idea of "Satan" as a person, which was not a concept in Jesus's time. They eliminated the articles before this word twice to reinforce the idea that "Satan" is a personal name rather than a noun describing a concept, the adversary. (More about satanas and life's adversity in this article.)

Jesus is making light of the accusation against him. The part about "satan" is the setup. The punchline is a question: "How exactly will it stand, this realm of his?"