A very minor thing, but I'm quite annoyed by the fact that The Book Ghosts (at sage cat area) are not affected by heal while monsters like Dreamy Ghost's are affected . Not sure if there are other monsters out there with the same issues.
fwiw, they've always been immune to heal. https://bbb.hidden-street.net/monster/the-book-ghost (not sure if you knew this). Logically it would make sense for them to be weak to heal, but Nexon isn't exactly the best at logic.
A ghost normally is a soul of deceased living creatures, while book ghost is the memories of human (for example Tom Riddle's diary in Harry Potter and the Chamber of secrets). Heal in most RPG is a bless from heaven that ease the pain of living beings while send the tormented soul to afterworld, while memories is not considered "soul" in the classical games. Sound logically enough for me.
But the journal in Harry Potter is literally 1/7th of Voldemorts soul. It's not a memory, it's his soul coming back to life as it sucks the life out of Ginny.
