Ina, visit archiveofourown.org's Penny Dreadful section (TV shows) and you'll find tons of excellent ones. I really recommed ScorpionMother (she's also a great friend of mine who I met through fanfic writing for PD) and Su_Abeille's stories. You will love them for sure! I would suggest some of mine, but either they're a bit old or I'm too evil and naughty and abandoned them. I do have some one-shots though if you would like to read.
Ethanessa Fanfiction Links:
Penny Dreadful (TV) - Works | Archive of Our Own (The PD Homepage)
our demons make us who we are - Iverna - Penny Dreadful (TV) [Archive of Our Own] (This one's gorgeous, read it yesterday!)
The Blessed Light - Jean Genie (Su_Abeille) - Penny Dreadful (TV) [Archive of Our Own] (This one is so, so good it made me cry... of joy)
Jean Genie | Archive of Our Own (Su_Abeille's profile because she is just too damn good of a writer)
ScorpionMother's profile:
scorpionmother | Archive of Our Own