Two Virmirs. The universe is going to explode!
If that was a requirement for universal detonation, then we're overdue an explosion by quite a few Virmirs.
But yeah, given how this story arc has been emphasizing repeated how Virmir is nothing if not efficient, it only makes sense that he'd escape his prison a few second before he entered it. I'm almost surprised that he didn't escape just as the dragon awoke and stopped it from destroying the tower.