Pro tip before the Update is live: Don't start to massacre the black pearl birds or Jewel birds for masks, they can only be obtained through the new legacy system

[Neyreyan_Youtube]

Some people have said the new bird masks are obtained by killing those birds but that's false:)
The Pearlbird mask has also been nerfed by 5% so it offers only a 15% increase to speed in the experimental branch.
The black mask offers + 17% and the Jewel bird 19% so....in order to get the 19% bonus to movement speed you need to play 3 characters, the first will get the pearlbird mask and leave it in a legacy chest so the 2nd character gets the black one....wich he puts in the legacy chest and finally the 3rd character will get the jewel bird mask.
Great design devs! So to get the coolest gear you have to play the game at least 2 times but the jewel mask needs 3 restarts.
So might as well finish all the story lines and in the end get the Jewel Bird Mask and the White (legacy) Kintsugi armor set.
Also confirmed on video and tried with other items, the fancy items are mostly legacy items:
https://www.youtube.com/watch?v=O4YNW3gDFo4