Not really spoiler just a better of explanation of what we already know:
The Sovereigns (formerly known as monarchs) and the Rulers have been waging wars against each other for a long time. The Shadow Monarch is the source of Sung Jin-woos powers but we don’t know how or why yet. The rulers can lend their powers to vessels. Four of the national level hunters are those vessels. The other monarchs are going around killing those big hunters since they are vessels. Also the Monarchs and the Rulers are planning on using earth as their battlefield for their big war.
Hope this helps :P
The comic never really addresses why tf they sent the MC into the novel in the first place. If it was just Eunha trying to get rid of him why didn’t she sink the book the first time?
maybe bcs that might be too far? Mc doesnt really do anything wrong to her, so maybe her conscience held her back. I still would've prefer if author explained this loophole too ngl
She probably didn't think her brother would find a way to bring him back lol it's not a plot hole, just look back at the time where she found out he was awake, she was surprised he managed to get back because she didn't know it was possible.