The horrors of the Immeasurable Kalpa are well-known to those with a bit of insight.
Take, for example, the Dragon and Phoenix Calamity, which led to the near extinction of the Dragon Clan, Phoenix Clan, and Qilin Clan, causing them to exit the stage as the protagonists of the Primordial Continent.
The same goes for the War of Witches and Demons, leading to the fall of both the Witch Clan and the Demon Clan.
Although the Demon Clan can never be truly extinct due to their existence mechanism, the new protagonists—humans—are in direct opposition to them.
The survival of the Demon Clan is thus quite bleak.
However, in all Immeasurable Kalpas, the initial stages of the calamity are not particularly severe.
Generally, it is in the mid-to-late stages that the calamity fully manifests as a killing calamity between heaven and earth!
The Dragon, Phoenix, and Qilin Clans were nearly wiped out in the final great battle.