The Bloodleaf object in Madeline's Garden of Mazes for the Rusty Sword sidequest is bugged and cannot be interacted with properly. Dekarous is aware. A fix will be uploaded later today. A 3.1 update is planned, which will also contain some additional Narcissa scenes and the ability to break the Ember Seal to get a sneak peek at Mary's Emerald Throne, the fourth realm.
You should be able to open Narcissa's door just by breaking the Starlight Seal from Madeline. Dunno if the game is coded to also need the Blackstone Seal to be broken as well. Either way, that's the one trigger. Dekarous also confirmed that saves from previous versions are always planned to be compatible with each successive update.
By the way, the staggering volume of people jumping into the thread requesting saves as soon as the update drops is just sad. The game isn't terribly hard or long if you just use your brain a teensy bit.
For anyone having difficulty beating Narcissa, here's my foolproof strategy: Equip the Golem Sword and make sure you have the Soul Link spell, then enter battle. Guard for at least three turns, then cast Llavanya's Fury twice to buff your attack to max (this should last 4-5 turns). Soul Link is tied to your attack stat, so cast Soul Link next to heal yourself to full and take a chunk out of her health bar. At this point you should've built up a significant amount of TP from guarding and taking damage, so use Precision Strike a couple of times (the only reliable way to hit with the Golem Sword). Cast Soul Link again to keep yourself healthy: as soon as Narcissa drops below 1/4(?) health, she does an extra-damaging move as a reaction along with any other attacks that turn, which can kill you if you weren't watching your health before that blow. Any remaining health can be dealt with easily after that.