Welp from what i remember from the novel that shez from the recent chap is the war that happened a long time ago, which is the time of the shadow monarch, also its a war between 4 forces, the shadow monarch side, monsters, devils and the gods more like the angels shez but i think its the gods or some shez, anyway so that war was dominated by the shadow monarch i kinda forgot if he lost or what, but its a war a long long war that destroyed their own world so the other side of the winged silver shez made a dimensional shez, so basically the birth of the dungeons and awakening in earth, just for the sake of continuing the war, to make it stop or shez well stuffs happen and jinwoo would make a really goodamn decision at the end (kinda don't wanna spoil this since its the best part) to make the war stop
And about the two hearts the extra heart belongs to the shadow monarch, its supposed to take over him or shez the reason why the four winged shez jinwoo fought says that the king would awaken from his slumber cause the shadow monarch is supposed to take over his body thou it did not happen, well its a good part I can't wait to read that part
I'm so lost and it's ok if you spoil me so pls just explain it somebody ಠ_ಠ