First Civilization Era: The Destroyed Continent

The reason previous civilizations feared the Law-Rulers and Honkai to an extraordinary degree was largely because two continents were severely damaged, or even destroyed, by Law-Rulers successively.

The first was Australia. Fu Hua's captain, Himeko, became a Law-Ruler during the Seventh Honkai and incinerated the entire continent of Australia. However, judging from Fu Hua's background chapter on becoming a Flame-Chaser, Australia was rebuilt to a certain extent.

The destruction of the Mu Continent pushed the fear of Honkai among previous civilizations to its absolute peak. During the Ninth Honkai, the Herrscher of Earth created a pseudo-black hole, [destroying] the Mu Continent—the most prosperous place on Earth.

Note: It was destruction, not consumption. The Herrscher of Earth's abilities were far from capable of creating a black hole large enough to consume an entire continent.