Aside from this, does it really mean anything anyway? Jesus encounters demons possessing humans who call themselves by the plural as well. Are we supposed to say that they're calling themselves god too?
Notice how the demon refers to himself as us. "Have you come to destroy us?" But the scripture doesn't acknowledge the plural. "Jesus rebuked him," and "the unclean spirit," are how scripture refers to the demon. Hmmm... sound like anyone who "revealed a book" to a so-called prophet? You know it does! That's because Mohammad was visited by an unclean spirit, and the unholy book Quran was revealed by it. The use of plural means nothing. It's an imitation of the plural in essence but one true God.Mark 1:21–28
Jesus Heals a Man with an Unclean Spirit
[21] And they went into Capernaum, and immediately on the Sabbath he entered the synagogue and was teaching. [22] And they were astonished at his teaching, for he taught them as one who had authority, and not as the scribes. [23] And immediately there was in their synagogue a man with an unclean spirit. And he cried out, [24] “What have you to do with us, Jesus of Nazareth? Have you come to destroy us? I know who you are—the Holy One of God.” [25] But Jesus rebuked him, saying, “Be silent, and come out of him!” [26] And the unclean spirit, convulsing him and crying out with a loud voice, came out of him. [27] And they were all amazed, so that they questioned among themselves, saying, “What is this? A new teaching with authority! He commands even the unclean spirits, and they obey him.” [28] And at once his fame spread everywhere throughout all the surrounding region of Galilee. (ESV)