Here's how it works with millicent - her story is definitely going to end in tragedy no matter what choices you make but there's still something meaningful about how it all plays out. The most important thing to understand is that when you reach that final confrontation youll have to choose between helping her fight her sisters or taking the darker path and betraying her.

If you're wanting the most emotionally satisfying conclusion, helping her against her sisters lets her make her own choice about removing the unalloyed gold needle, which feels more true to who she is. She'll still pass away, but it's on her own terms instead of becoming another scarlet valkyrie. Something interesting to consider is that either path leads to different rewards - helping her gets you the rotten winged sword insignia and access to miquella's needle, while betraying her gives you millicent's prosthesis.

The whole questline really ties into bigger themes about cycles and choice, especially with all the scarlet rot stuff. Even though you cant save her in the end, the way she chooses to face her fate tells us a lot about breaking free from destiny. Just keep in mind that once you make your choice at that final moment, there's no going back so think carefully about how you want her story to end.