Endacopia Lore Theory

Sitri's mark, we find in the book about endascopia in the surgeon's lair in Ending C.

Sitri, the Prince of Passion and Obsessive love is decaying and dying because the reign of the demons in hell has caused the land to be barren and bereft of love and thus Sitri's command and power. The surgeon, a man that once was, and the Bride, a woman that will be, their passion give heart and the sacrifice of the surgeon and mellow to allow ascension feed Sitri for one millennia more. This is the reason why Sitri is dying and why the sacrifice in Ending C give him life once more for a time, and for a price. Love and Life freely given.