Raziel always appears as a normal male of a humanoid race with a sack and axe. He typically wears armor and a helm or hood. While he may give or take from a person, he is not above bargaining. Though his price is high and he typically asks for women (esp a bargainers full grown daughter), wine, feasts, song, and other desires reflective of his worshipers of high and luxurious value.
Interactions are always random and are a 50/50 blessing/curse. Items from the sack are randomly determined and have twice the chance of being cursed.
If using an older game use the rules for a Storm Giant's bag.
In a newer game roll randomly.
The old school applicaitons of Raziel are obvious as are his 3e/4e magic item economy applications.
(Thanks to Jeff Reints for the ispiring image)