Revelation 9:15
And the four angels were loosed, which were prepared for an hour, and a day, and a month, and a year, for to slay the third part of men.
Cross-references
Revelation 9:5's locusts torment but do not kill; here angels kill a third. Direct contrast in judgment severity.
Revelation 9:10's locusts hurt but don't kill; here angels kill a third. Contrast between non-lethal and lethal judgment.
Revelation 9:18 describes the three plagues that kill a third of mankind, fulfilling the release in 9:15. Same sixth trumpet event.
In Rev 9:14, the command to release the four angels is given — this is the direct cause that leads to their release in 9:15.
Revelation 8:7's first trumpet destroys a third of the earth; here a third of mankind is killed. Pattern of fractional destruction.
Revelation 8:9's second trumpet kills a third of sea creatures; here a third of people die. Recurring 'third' destruction across trumpets.
In Rev 6:8, Death kills a fourth of earth — this earlier fractional judgment (one fourth) is now escalated to a third, showing intensifying wrath.
In Rev 8:12, a third of celestial bodies are darkened — this same fractional judgment pattern (one third) reappears here as a third of mankind killed.