[quote=@6slyboy6]
But I guess that his ability to change himself can probably make him the single biggest charcater for a [b]brief[/b] amounts of time.
[/quote]

Used correctly, the spy/thief/assassin is incredibly important most of the time. I mean, think of all the things Adventurers need to know. "Where's the thing?" "Who are we fighting?" "What does this do?" The spy can come up with this information, and since his skills are always in demand among the kingdoms, he can charge fairly high prices, depending on his client, and eventually provide a steady income to spies who, in turn, work for him. A master of knowledge that shouldn't be known and procurer of things that shouldn't be procured, whose collection never stops growing. What use is a sword when the guy you're coming after can hide anywhere and hear you coming from a town away?

Granted, it isn't as practical as the other kinds of skills in immediate pickles, but that's what sneaking is for... And the burlap sack...