Mask of the Shapeshifter
Cape of the Red Prince
Lute of the Merryweather Bard
Needle of the Outlaw Rogue
Bicorne of the Sea Beast
Are the items mentioned. I do recall that at one point I read that the mask of the Shapeshifter was a usable item in that it could cast Disguise Self or something.
I honestly hope that this is not the case and these are just cosmetic items.
My own thought is that I'm less concerned about whether they provide abilities rather than being simply cosmetic, but more that I don't want one to be strictly better than all the others. I'm fine with them all being cosmetic, and I'm fine with them all being useful. I'm not as happy with one being useful and the rest cosmetic.
It would be nice if they just gave little bonuses that didn't make any more of an impact that items you'd find in the first act.
I'd imagine the Cape would add a bonus to intimidation or other Cha checks.
We haven't seen any bonuses on musical instruments, but maybe the Lute will give you the musical instrument proficiency, and/or add a song.
I'd imagine the needle is just a dagger with a poison effect.
The hat could have a simple bonus to a proficiency, maybe perception?