Regarding the fact that the Demon Lord abducted the heroine after passing through the book...
[Original male protagonist: vomiting blood. JPG]
Two female protagonists, quick time travel, and a bit of a Mary Sue in terms of planes (the author brings his own lightning rod, and the one who avoids lightning will retreat on his own, so he doesn't force it)
(Note: Female Demon Lord)
After being injured and falling off a cliff, the Demon King was accidentally bound to a system called 520. "Ding dong is the host's first novice mission card, which inspires the male protagonist's hatred value x10."
On a dark and windy night, the silly and sweet heroine, who was weak and unable to take care of herself, seduced the female devil...
Demon Lord: "I thought I was at least the one above..."
Concept: What will happen when the Demon Lord passes through the book?