This manga is interesting. Dark and really high paced. I think the MC staying in MW world is a much better ending than if she went back to earth. Even though both have their own pro and con. Lets compare them:
* In MW world
PRO: MC have her elf friends (or even family), loved and acknowledged by all. She's peerless, strongest of all. She even has MWs as her cards.
CON: There might be some other MWs suddenly reincarnated there in the future. What's stopping god from doing that, since there was three black MWs? The MC would always be afraid of the sudden appearance of other MWs. The scariest part is when other green MWs comes...
* On earth
CON: Elves would get persecuted, researched, tortured, etc. There are two more MWs aside from the MC which can really threaten her rule. Normal humans on earth can fight back much better with their much superior number and technologies. Satellites and wiretaps can spy on the MC. Bullets, bombs, missiles, and poisons can kill her. She would never be able to rest easy unless she killed all other MWs along with almost (if not all) normal humans.
PRO: Once MC "cleansed" the earth, there is no threat of new reincarnated MW.
I liked this. The romance part was never really explored but it's okay. Though I hoped that there is no sequel because the ending's already good enough. A parallel would be alright though. 😄
