Leviathan - Chapter 158

Im sure I saw a certain theory on another website, I forgot which website it was unfortunately! But I’m sure that the theory is like..

The sea devils were test subjects so that humanity had the ability to be able to breath underwater ever since the floods started to come in. Somehow, it failed. The sea devils escaped and made their own nests, plotting revenge against the researchers. Not only that, humanity started to experience a new disease that Bota and Lita’s mother had. I forgot the rest but its similarr..