So, I am floated the idea verbally that Revelation is composed in the Markan Community.
I’ll give you just a few reasons.
First, the internal structure of Revelation 4 – 19 is one of circles within circles within a giant circle that is Genesis 2-3 and Revelation 21-22. This is a feature of Mark as well. There is also a noticeable pivot in both books, with Mark’s pivot on the Mount of Transfiguration and Revelation’s in chapter 16.
But more than that – there are the parenthetical hidden messages. For instance, in Mark 13.14 when the author turns to the audience to remind them that they need to pay close attention to what he is saying. We see this likewise in Revelation 13.18 and 17.9, 15.
Not only that, but the style of the Greek is… butchered.
Anyway, there you.