fantasy idea | thinking outloud
I keep forgetting to share this idea but once, at work, I was watching a (cis?)woman unlock a door, and the way I was looking at her hand, it looked like she was opening the door WITH her very long (at least a few inches [~5cm]) nail, like a skeleton key....SKELETON-KEY FINGERNAILS!!
so now if you are looking for that 'extra' element for your witch/magic character please let me suggest,
skeleton-key fingernails
fantasy idea | thinking outloud
to clarify, the nails look normal, until they're close to a lock, at which point the tip of the nail will magically transform into the needed shape to open the lock
works on all old-school locks, doesn't work on electronic number pads and/or magnetic locks
idk enough about vaults to say whether it should open one, so I'm just gonna be lazy and say it wouldn't 
