Although you may have been reached at solution by this time, let me post for later player.
You can 'mug' or 'steal' from Thor(?) loacted in 81~90F of Eastern Cave.
It is recommended to down directly to 90F for comfortable stealing.
With default command skill in 'steal' and pressing FF button on left top of screen, it would be available to steal a Bead within about 200 times attempts of stealing.
Devine Bead is also drop and stole item of the last boss, Dark Assembly.
So without utilizing the above tip, normally you can master all kind of jobs
in 4 plays or so. (There are multiple endings in this game.)
