Hi Joshuastone,
I wasn’t inquiring about “who” the fallen angle was, but how to read the sentence. The Greeks, Hebrews, and other languages did not have punctuation marks: period, comma, question mark, hyphen, dash, parentheses, apostrophe, ellipsis, quotation mark, colon, semicolon, exclamation point, in their writings. It was in the late 15th century and 16th century that the use of punctuation marks were used. http://www.sjsu.edu/faculty/watkins/punctuation.htm

One thing that the Greeks, Hebrews, and others used were accent and diacritical marks within their words. These were mentioned by Jesus as “the stroke of a letter”. “Truly I say to you that sooner would heaven and earth pass away than for one smallest letter or one stroke of a letter to pass away from the Law until all things take place.” (Mt 5:18 NWT) These were most important because changing the smallest letter or stroke would change the complete meaning of the word or words within a sentence. The word used by Jesus was keraia (ker-ah’-yah) meaning: a little horn, extremity, apex, point; used by grammarians of the accents and diacritical points. Jesus used it of the little lines or projections, by which the Hebrew letters in other respects similar differ from one another; the meaning is, “not even the minutest part of the law shall perish”.

So, here’s the point I was trying to get an answer for. Who gets the key to the abyss, The angel who blow the horn or the “star that had fallen from heaven to the earth”? If you read it as written, it is:
“The fifth angel sounded and I saw a star from heaven which had fallen to the earth and the key of the bottomless pit was given to him.” ( Rev 9:1 NASB ) His name is Abaddon (destruction), and Apollyon (destroyer). He is Satan!

It takes a while of studying other scriptures to get the sense of what is being said, and its application. In this particular scripture it is necessary to identify the difference of the angel with the horn and the star that “falls” from heaven. When comparing other verses mentioning stars as metaphors or figurative objects, we can gain a better understanding of what is truly meant. The Greek words used are aster, astron, and phosphoros. The last word is where we get the English word phosphorus. It has the meaning of “light bearer”, a compound of phos (foce) + phoros (for’-os). It is translated as “morning star”. This word appears to be used only once in the Greek scriptures (NT) by Peter. “So we have the prophetic word made more sure, to which you do well to pay attention as to a lamp shining in a dark place, until the day dawns and the morning star [phosphoros] arises in your hearts.” (2 Pe 1:19 NASB )

In the other two occurrences, at Rev 2:28 and 22:16, the words used are proinos (pro-ee-nos') = (pertaining to the morning) + aster (star). Then, there is the word where we get the English word astronomy. It is astron (as’-tron), meaning a group of stars, a constellation. “There will be signs in sun and moon and stars [astron],. . .” (Luke 21:25a NASB )

Now, . . . Let us get back to that star mentioned in Rev 9:1. It said that this star had “fallen to the earth”. It doesn’t say “come down from”. The Greek word for fallen is pipto (pip'-toh) with the meaning in this case: metaphor, to fall under judgment, came under condemnation. I.E. “Jesus said to them: ‘Did you never read in the Scriptures, ‘The stone that the builders rejected, this has become the chief cornerstone.’” (Mt 21:42a) “Also, the person falling on this stone will be shattered. As for anyone on whom it falls, it will crush him.” (Mt 21:44) “Immediately after the tribulation of those days, the sun will be darkened, and the moon will not give its light, and the stars will fall from heaven, and the powers of the heavens will be shaken.” (Mt 24:29 NWT)

When we read more of the account in Revelation, we will find that this fallen angel is Satan. This is based on the results that are affected by his opening of the abyss. “He opened the bottomless pit, and smoke went up out of the pit, like the smoke of a great furnace; and the sun and the air were darkened by the smoke of the pit.” (Rev 9:2 NASB ) “And He said to them, ‘I was watching Satan fall from heaven like lightning.’” (Luke 10:18 NASB )

This is similar to what happened previously. “The third angel blew his trumpet. And a great star burning like a lamp fell from heaven, and it fell on a third of the rivers and on the springs of waters. The name of the star is Wormwood. And a third of the waters turned into wormwood, and many of the people died from the waters, because these had been made bitter.” (Rev 8:10-11 NWT)

This particular angel is named Wormwood, apsinthos (ap'-sin-thos). This angel is likely one of those that Peter mentions. “. . .He went and made proclamation to the spirits now in prison, who once were disobedient, when the patience of God kept waiting in the days of Noah,. . .” (1 Pe 3:19b-20a NASB ) The prison is the abyss. We are also told of the angel who delayed the message to Daniel. (Dan 10:13, 20) We know that the symbolic “waters” are explained, “The waters which you saw where the harlot sits, are peoples and multitudes and nations and tongues.” (Rev 17:15 NASB ) What we know to be called demons, are rebellious angels. They are let out of the abyss by Satan to bring about all the plagues on mankind. That is why the figurative “waters” are brought to blood.

“Instead, they stubbornly followed their own hearts, and they followed the Baʹal images, as their fathers had taught them to do. Therefore this is what Jehovah of armies, the God of Israel, says, ‘Here I am making this people eat wormwood, and I will make them drink poisoned water.’” (Jer 9:14-15 NWT)