>>1780084
>The dryad
do you mean the Mandragora? The Dryad Girl cures poison and petrification, while the Mandragora is the common plant, and the one who screams (or I guess in her case just kinda cries really loudly) to paralyze people. She is good too though.
But really Perili is probably a contender for strongest low-rarity girl. I would also highly recommend Shiijime/Mushroom Girl as well. She can generate a nigh infinite army of clones, and if you have Holy Prayer (and if you don't the dungeon for it's coming up this weekend) her skill cooldown is so short that she can reapply the regeneration buff the second that it ends, which even heals tokens, and it's surprisingly handy.

On the subject of lower rarity girls, I managed to clear one of the Epic Or Lower Only challenges today, which was pretty fun. Charis did most of the heavy lifting, taking down the dogs (she actually sniped the ones in the bottom corridor from her spot with her Rock Breath skill) and the Dullahan but Perili mowed a lot of the minions down too.
(I would also suggest Charis/The Cockatrice Girl, but she needs her EX2 Skill to unlock her full potential as her normal one is not nearly as good at it is)