L' Appel du Vide (Black Butler Reader Insert / Various)

"There will always be balance. Cruelty and kindness, pessimism and optimism, demons and angels. There is no way around that," - Seraphine Evangeline. ⚜⚜⚜ When (Y/N) Victoria Mithridates' family is completely wiped out by a mysterious affliction -save herself- she struggles to defend her family's legacy from those with selfish and bitter intentions.
Pitted against those who believe her unworthy of her birthright, she unwittingly calls upon a divine entity, who came offering her a proposal she couldn't refuse. Now, with her motherly companion behind her, she is now able to investigate exactly what kind of 'disease' killed her family, and if it was really such an unfortunate disease at all.
After all, the Mithridates family have been building immunities to sicknesses and poisons since they were young, as is tradition, so such an ironic occurrence is hardly likely. Save it was actually a nigh-successful attempt to destroy her entire lineage -and possibly- the entire country.