They already see justice inasmuch as they are given white robes in the presence of God. The full vengeance on their enemies could occur in part as the Lord sends the second, third, and fourth horses (with their plagues of war, hunger, sickness, etc.) on the earth, and it will occur in full on the day of the Lord’s return in glory to judge the living and the dead.
11 Then they were each given a white robe and told to rest a little longer, until the number of their fellow servants and their brothers should be complete, who were to be killed as they themselves had been.