@jj_reads_manga
they are two different kinds of evil, this girl uses everyone and throws away those who are of no use to her anymore, and she actively eliminates those she can't use anymore before thy can turn against her (like the hero and her servants). her evil certainly reaches farther than Flare's, but on the other hand, Flare's evil feels far more concentrated, she doesn't as directly effect those around her, she seems to view them more as tools to use for her goals (as such she will kill a lot of people if she deems it necessary, but does not do so as often or on a whim like this princess does), and if you ARE deemed as particularly "useful" then she'll go a hell of a lot further to ensure you remain useful to her regardless of your opinion...and at extreme cost to you if you are worth using but not willing to be used...
so I guess it's a pick your poison moment, if you are some random person in the kingdom...Flare's a little less likely to kill you, but if you are someone important...then they both suck, but hey, at least if this princess gets her way you'll (probably) just die, Flare would drug you, enslave you, and use you beyond your limits, forcing you to stay alive for her convenience and making you suffer horribly the whole time