Absinthe Addams and the forgotten identity

Summary: Dumbledore should have never left Harry on the front steps for so long unattended, especially on Samhain. What if a certain enchantress from one of the darkest pureblood families known to date found him and decided to raise him as one of her own? What would happen to the Wizarding world? The answer: Pure chaos. Dark!Powerful!harry Crossdressing! Dumbles/Ron/Ginny bashing!