Leviathan, as the sovereign of the ocean, was virtually omnipresent in the sea, and it was these creatures that hindered the development of humanity in Otherworld.
Leviathans were inherently irascible, with a strong desire to attack and a keen sense of territory. Anything that passed through their domain, be it other Leviathans or large oceanic creatures, or even ships merely sailing on the surface, could hardly escape their claws.
One could say that for the people of Otherworld, Leviathan was akin to a natural disaster. Wherever possible, they would not allow these giant creatures to coexist with them but would mercilessly annihilate them entirely.
However, even with that said, Luo'er still felt a sense of discomfort in his heart. After all, it was very likely that the Leviathans had attacked them at Tana's instigation, a situation reminiscent of two tigers in a fight where a hunter watches from the sidelines, which made Luo'er very uncomfortable.