Accepting any Hypothesis on what these NPCs actually do. I'll go first:
Transmogrifiers changes your gear to have the appearance of any other gear you also own, as long as it is the same type. For Example you can Change your [Kingdom's Heart] to have the model of [Zulian Ward]. Lord of The Rings Online already has a feature like this.
Void Storage, where you can pay money (or Shards or marks or whatever) to turn a soulbound item, into an account-bound item.
Any other guesses on what these features could do?