Hi

I read a vampire manga where some people capture a vampire and want the secret to immortality. But the vampire refuses to talk or eat. A cult forms around it. There's a scene where someone is hunched above a bleeding woman drinking her blood with a straw. Does anyone know what it might be? I really liked it but it was so long ago. There's a scene with a church window of stained glass that is in the form of someone drinking blood through a straw.

Someone on /a/ said it was by /a/'s favourite tranny mangaka but refused to give more clues. That means absolutely nothing to me please help lmao

Pic unrelated
Thank you!!