They're the most dangerous, most powerful, most evil monsters who ever existed in Eden. Jovian & Jacqueline, Aeon, Seraph, and Twilight all hold the title of Dark Queen, and rightfully so.
But who do YOU think is the weakest Dark Queen? They're all very powerful, of course, and to think of ANY of them as "weak" would be a VERY unwise move on anyone's part. But which of these four incredibly vicious ladies is at the greatest disadvantage when compared to the other three?
In my personal opinion, from what I've seen so far in the series, I think the weakest Dark Queen may be Aeon.
Allow me to explain. Aeon certainly has a lot of advantages: she can control time, stop time for all those around her, AND can predict the future to some degree. But besides these powers, she's mostly just an ill-tempered butterfly with a lot of strength and a TON of arrogance.
When compared to the other Dark Queens, they all seem to trump Aeon in some particular area.
Seraph can take away any monster's free will and use them as her personal slaves. Even the other Dark Queens cannot resist her control. Aeon herself admitted that she would be no match for Seraph, even with time stopped around her!
Twilight, being the Dark Queen of Magic, is more in tune with the Ether than any other being in the world. Chances are, she probably knows how to counter Aeon's chrono manipulation and omniscient sight. Not to mention, Aeon has a personal grudge against Twilight, whatever that involves. So, it may be in Aeon's best interest, and personal satisfaction, if the Reaper stays locked up.
Even Jovian & Jacqueline would be a nuisance to Aeon. First of all, neither half of the Gemini can die, so Aeon's minions wouldn't be able to kill them off. Secondly, Aeon can't break the Gemini's minds through torture because Jovian & Jacqueline can't feel pain by any traditional means. They'd probably just laugh in Aeon's face as she tries over and over and fails each time.
I know Aeon may have more than just time manipulation and infinite knowledge up her sleeve, but, as things stand, the other Dark Queens seem like they would be a bigger threat if and when they're let out. While they all enjoy being "hand's on", Aeon is more of an indirect villain: one who carefully plots and strikes from the shadows, paving the way to her victory while keeping everyone in the dark. But this may very well be what trumps the other Dark Queens.
Raw muscle and powerful magic are good, but a clever plan can topple a whole army.