The 7th trumpet is the start of the third terror and ultimately marks the beginning of Christ’s return.
“Then the seventh angel blew his trumpet, and there were loud voices shouting in heaven: “The world has now become the Kingdom of our Lord and of his Christ, and he will reign forever and ever.” Revelation 11:15
After the 7th trumpet, the kingdom of the world will eventually become the Kingdom of God.
The 24 elders celebrate God with a song of worship. They praise God for his might, eternal nature, power, the blessing of his people, his great name, and his judgment (see Rev 11:16-18).
This trumpet marks the start of another round of judgments that will ultimately lead to Christ’s return.