The fourth vial was poured out as the Jesuits caused the bloody Napoleonic wars with countries that had previously banned them, so they were getting their revenge.
The ‘sun’ represents the mighty military leader Napoleon, who within the space of eight years, scorched every kingdom in Europe, from Naples to Berlin, and from Lisbon to Moscow.
Elohim used it to exact revenge against the countries that had shed the blood of His followers.
But the leaders of the countries did not repent, they blasphemed Elohim for His punishment.