Because I read it and read some explanations in the chat throughout the times it was updating.
Because I've read and re-read it many, many times in the year that passed between the Korean release of the last raw chapters of season one, and the start of the second (which overlapped with the time around which season one was finally completed here). I've read season one many , many times, first in Korean (using mtl) then in English and even some in Spanish... and even re-read a few chapters a few times, after that.
To be honest for me I had to do research and come to a slight understanding that my tiny pea brain was gonna hurt trying to understand why they (Osiris mainly) did/do the things they did/do. After reading it a few times and doing at least a little bit of research and get a little bit of history to back up the book I feel like it would be easier to understand. It also becomes much more enjoyable...hehe
cuz i've read the kane chronicles by riordan before that's why im familiar with the setting
this manga is too big brain I got to chapter 4 before I gave up because I was so frustrated and confused. To those who understand this manga "HOW!?"