In the north of the Lower Heaven, there was a sea that is as dangerous as it is vast. The Dark Sea, the home of numerous oceanic beast that holds terrifying powers. To fight with beasts on their own turf was practically suicide and these beasts despite being aquatic have the ability to fly so even if an Immortal flew up, the chances of getting dragged to the depths was high.
There are only three known ways on how to travel safely across the seas of the Lower Heaven. First would be to board a Warship that is designed to fight off the beasts, second would be to become strong enough to command fear of everyone in the seas, and the last one would be not traveling at all and just travel through transportation arrays.
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