Plot / Quest Summary
mina & corrinthe are old travelers who come into yharnam from far away, seeking knowledge to better their kingdom, which is suffering from a vicious ashen blood plague ( similar in nature to loran, where the town turned to ash under the weight of the plague ). corrinthe comes to yharnam first out of a sense of duty, being their kingdom's heir; mina follows sometime after to bring her home.
the quest begins when the player finds a tarnished pendant hidden away in old yharnam, which has an item description speaking to an old fable about two meddlesome outsiders.
there are two pendants -- a ruby sigil, and a turquoise rosary -- but you can only get one per playthrough per run. ie., you find the sigil on your first playthrough, and then in the same spot you find the rosary on your NG+ run.
once you find the ruby sigil, if you go to the hunter's nightmare, somewhere tucked away & relatively peaceful you can find mina. if you speak to her, you'll find she's very friendly & warm, but she expresses that she can't quite remember her name, how long she's been here, or even where "here" is, but she knows she's looking for something. she can't give you details yet, but as you defeat more of the nightmare's bosses & expose more of its secrets, you can return to her & learn more bits & pieces of her story: she comes from a kingdom far away; her home was besieged by the ash plague; she was a priest in training before she came to yharnam ... once she manages to recall that this "something" she seeks is actually a "some
one", you are prompted to give her the ruby sigil & jog her memory for good: she urgently tells you now that she's looking for the princess, a valiant knight & impeccable scholar, whose studies into life could not lead to a cure, and so sought to gain knowledge from yharnam's miraculous blood ministers. having been struck by clarity, she exclaims that there's still time to find the princess -- and the next time you refresh the map, she's gone. ( prior to giving her the sigil, you can speak to mina anytime to get a free blood vial ).
near the place you originally found her, a pathway has now been opened that leads to a hidden arena with a giant darkbeast. in its hand it holds a crusty looking sword, which it uses with very little tact or style.
although this isn't officially a boss fight, it functionally is one; however, upon defeating the darkbeast, you don't get any drops besides echoes ... and as well, the corpse of the darkbeast does not fade away.
to progress further, you must kill the orphan & put the nightmare to rest. after completing the dlc, you can return to the place where the darkbeast was felled ... only to find no darkbeast, but the corpse of a human, and kneeling besides the human ... is mina!!
if you try talking with her now, you'll find her crying in a haunted & harrowed fashion, speaking mostly to herself, saying things about how bittersweet this reunion was, how long it's taken to find this person, but how upsetting it is to both find their dead body, but also, to be hit with the realization that their kingdom has almost certainly been reduced to ash in their generations-long absence, stuck here in the nightmare.
pressing her further will make her finally realize you're there, forcing her to try composing herself. she apologizes for being out of sorts, but thanks you for your help in returning her memories, and also in helping "the princess" find herself once more. her final lines of dialogue will be her handing you one last blood vial, and then, if talked to again, she will apologize once more & somberly say, "i'm afraid i've nothing left."
if you leave the area & return, you will find her dead alongside corrinthe; if you check her corpse, you will now be able to reclaim the ruby sigil -- however, this time it appears in a different form. you initially find it in its "dull" form, but now it's "glimmering", the aged patina removed. taking this back to the dream, this unlocks the princess's -- or rather, of course, corrinthe's -- weapon & armor set, which you can buy with insight.
the sword functions similarly to the holy moonlight sword, but is attuned to blood instead of arcane, and has the additional benefit of boosting your beast meter if you use it transformed. the armor is reminiscent of dark souls, in that it's more medieval than gothic, speaking to how long these two have been trapped here.
thus ends her quest. if you kill her before completing it, she drops 5 blood vials.
in NG+, it plays out very similarly, but with a twist: instead of finding the ruby sigil, you now find the turquoise rosary mentioned earlier. and instead of finding mina tucked away in the nightmare ... you now find corrinthe.
she is much more closed off than mina, and she doesn't give you any items, but her arc progresses otherwise in a similar fashion. once you get to the point where you can show her the rosary, she leaves, having been struck with recall as mina did; in the spot where she once stood, though, you will now find a caryll rune. when equipped, this rune will let you summon her for boss fights & grant you additional damage with bloodtinge-scaling weapons.
now when you go to the darkbeast's arena, you will now find a different beast ... which of course, is mina. you can summon corrinthe to help with this fight, who will have additional dialogue at the end if you do. as with mina's quest, she will not appear by mina's corpse's side until the nightmare has been slain & she is returned to her human form.
when you speak to corrinthe here at the end, she is more in control of her emotions than mina was at this point, but she
is noteably more expressive than she was when you first met her; instead of speaking in fragments, she speaks in full sentences, reminiscing on the nature of dreams & nightmares, lamenting her failures, to her kingdom, its people, and to mina. if you press her, again she wordlessly hands you the glimmering form of the turquoise rosary, which unlocks mina's weapon & armor -- a trick staff that heals when transformed, and an armor set with exceptional resistance to frenzy & elemental damage.
and once you get that pendant ... they're both gone. in any further playthroughs, you can't find either of them in the nightmare again.
and that's the end ... of the bloodborne AU!!!
the idea that these two are stuck in different nightmare planes reliving things over & over, but not being able to remember because they're not "officially" hunters granted the ability to sincerely dream, is the crux of the drama here ... like, the idea that corrinthe learns about these planes from dreaming hunters, then artifically ascends to this plane to seek power & ultimately goes mad from it, and mina, who comes searching for her, learns about planes from the choir & wishes to visit to bring corrinthe home, but is sent to the "wrong" plane & so ultimately also loses herself to this thing that neither of them could fully comprehend ... yet despite this, both of them end up at each other's sides in the end ... brought together by the meddlesome good hunter ... this is the convoluted cosmic gay bloodborne tragedy that i crave ...