I know you said the great multitude in heaven in Rev 7 are the martyrs taken out of the Great Tribulation (so they do not go through it). I can agree with that, but then what happens to the martyrs after that? Many will still die in the Great Tribulation. I know the Sheep and the Goats Judgment is for the survivors of the entire 70th week, so what happens to those who die in the Lord during the last half, the Great Tribulation?
In Rev. 20:4 John wrote, “I saw thrones on which were seated those who had been given authority to judge. And I saw the souls of those who had been beheaded because of their testimony for Jesus and because of the word of God. They had not worshiped the beast or his image and had not received his mark on their foreheads or their hands. They came to life and reigned with Christ a thousand years.”
These are the martyrs of the Great Tribulation. They will be resurrected at the time of the 2nd Coming and will reign with the Lord in some unspecified way during the Millennium. Notice that while they will reign with Christ they are not called kings. This is similar to the group from Rev. 7:9-17 who serve God in His Temple but are not called Priests.
Neither of these groups belong to the Church who alone are referred to as Kings and Priests. The tribulation martyrs will most likely assist the church in a subordinate role like the Levites of Old Testament times assisted the Priests.