Translation
Then the fifth one poured out his bowl
upon
the throne of the BEAST
and its kingdom became dark,
and men were gnawing their tongues in distress,
Paraphrase
Then the fifth one set in motion the consequences demanded by the evidence, directing them at the source of COMFORTING LIES, FALSE STRENGTH AND STOLEN AUTHORITY, and it became the source of despair and distress instead of strength and authority; there was much self-imposed agony because the distress was so great,