Apollyon
Apollyon is Greek for destroyer.
Apostle
“Apostle” means a delegate, messenger, or one sent forth with orders. This term is applied in the New Testament in both a general sense connected with a ministry of establishing and strengthening church fellowships, as well as in a specific sense to “The 12 Apostles of the Lamb” (Revelation 21:14). The former category applies to a specific ministry that continues in the Church (Ephesians 4:11-13) and which includes many more than 12 people, while the latter refers to the apostles named in Matthew 10:2-4, except with Judas Iscariot replaced by Matthias (Acts 1:26).