"Throws dungeon" is a peculiar phrase, and there are numerous synonyms that could be used instead. Some of the possible replacements could be "cast into prison," "confine in a cell," "incarcerate," "lock up," or "put in the slammer." Additionally, you could use phrases like "sentence to the depths of a dungeon," "throw into the bowels of a dark cavern," or "banish to the depths of a subterranean lair." The phrase "throws dungeon" most likely originated from old-fashioned or fantasy-style language, but there are plenty of other ways to convey the same idea using more modern language and vernacular.