I would love an Ultra-Rare Currency that removes a faction requirement from an item

So rare that you probably would never see it , but if you do it's a game changer. A mirror of kalandra tier item. Something to chase for but probably not see.

What could it enable?

You could merchant an insane leveling item that is now permanently on your account.

You could enable a very rare legendary for all characters you own.

A long term meta-goal of a full factionless gear set.

Still couldn't trade it, because it would have no merchant tag, but you could be a bro and gift it.