Archway of Alteration

Passing through this portal causes an alteration in all Magic Items; each changes in Function, but possibly not form.  Any Potions carried are instantly tramsformed into different, random Potions, writing on Scrolls is replaced by different Spells, etc.  If there's a Magic Item Table for it, use it.  As for Misc Items, replace with completely different random Misc Items.  Let the dice fall where they may.

Shrewd Players with unused magic may attempt to use this for an opportunity to gamble on an "upgrade" of their current lot... sure, why not?  But, the Archway only works once/PC, and any previously transformed items will not change again.  Perhaps a Save applies, perhaps each Item  must Save, maybe a successful Save allows the Player to choose a favorite Item to be spared...