Why does the Tense change in Revelation 11?

I've noticed a few things interesting about Revelation 11.

First, because we often study the different subjects of Revelation in a compartmentalized fashion, we often think in verse 3 the "I will give power unto my two witnesses" is God/Jesus talking, and maybe it is, but that depends on how you interpret other parts of Revelation.

In the first verse of chapter 11 John writes "and the angel stood, saying" and most of the rest of the chapter is John writing what this angel says.  What Angel is it?  Well remember there were no chapter divisions originally, if you read through 10 and 11 uninterrupted, it becomes clear the angel in question is the angel who was the subject of chapter 10.

I also wonder about the "God of the Earth" the Two Witnesses stand before.  Is it a God they're severing or a God they are opposing?  "Stand Before" could be used both ways.  This title is used no where else in the New Testament, but Satan being the Archon of the Kosmos and God of this Aion leaves open the possibility that this title would most likely be used of Satan.  However it is used of YHWH in Genesis 24:3.   Is it a title of this Angel, who's feet are in the Earth and in the Sea?  It is also worth noting that we are before Satan is cast out of Heaven.

This Blog is predicated on my belief that Revelation should be interpreted chronologically.  But since I now notice much of chapter 11 is a character in the narrative describing future events, I am forced to wonder if there is some wiggle room here, and maybe somethings I have long viewed as being before the Last Trumpet sounds could be after.

And that leads me to the question that was the title of this post.  For verses 1-10 this Angel is speaking in the future tense, in the KJV at least.  Then in verse 11 it changes to past tense.  Maybe it's only in translations it seems this way.  I wouldn't be able to know.

It shouldn't be that big a mystery since lots of Prophecies are spoken in the past tense, and I've made a point of that in posts before.  The sudden change in tense is what seemed interesting here, as I was rereading Revelation 11 in the context of the observations I mentioned above.

In verse 14 it's no longer the Angel speaking, it's John setting the stage for the next Woe to happen, which is the Seventh Trumpet.  

The Angel in Chapter 10 also says the stuff he's telling John about pertains to when the Seventh Angel sounds his Trumpet.  So yeah I do now think everything this Angel Talks about is simply another angels on what happens after the Seventh Trumpet sounds.