[D&D] The Crook of Rao

This magical artifact was described by Gary Gygax in Isle of the Ape:

Amidst the gems and magicks we bore out from the depths of Castle Greyhawk's dungeon, was a small mace, a mere toy it seemed, albeit one fashioned of iron and silver and encrusted with carven gemstones. No geegaw, that. It is a most charmed implement of clerical power, the Crook of Rao. If that One is most peaceful and serene, nonetheless his word is not to be lightly passed off. Long and long Rao has refrained from any meddling here, but he left with us a token of his power. Devils and demons of the Lower Planes shudder at the mere mention of the object. Daemonkind flee in terror at sight of it, and we need it now!

While the adventure centers around a fetch-quest to recover this artifact for the forces of Good, the item itself is not actually detailed within the module, which feels like a major failing. Not only should it be usable in the final confrontation at the end of the adventure, but a party of 18th level characters should be considered capable of retaining it and using it themselves against the forces of Evil, rather than being expected to dutifully hand it over to their NPC bosses.

So, in an attempt to rectify that failing, here's my take on a full description of the item, so that it may actually be used and not just serve as a flagrant plot-device. [Note: I realize this item was "officially" detailed by TSR in the post-Gary era; I am intentionally completely ignoring that version.]

Crook of Rao

GP Value: 75,000

This artifact was created and left behind on the Prime Material Plane many ages ago by Rao, Flannish god of peace, reason, and serenity, who otherwise concerns himself not with the affairs of mortals. It appears to be a miniature ceremonial mace (1' long - too small for effective combat use) with a silver haft and iron head shaped as a stylized shepherd's crook. There are two star sapphires embedded in the head, and six carnelians surrounding a large topaz on the pommel. The value of the crook as jewelry alone is 25,000 g.p. As with other artifacts, it does not radiate any sort of magic. 

The crook can be used to cast a remove fear spell or cure insanity by touch. Anyone wielding the crook is immune to mental and psionic attacks and may cast a withdraw spell at 18th level effect once per day.

Any undead or Lower Planar creature (including those not normally affected by clerical Turning) struck by the crook is affected as if hit by an 18th level mace of disruption. Undead and lesser Lower Planar creatures are permanently destroyed; greater Lower Planar creatures are affected as if their material form was slain.  Once a month the wielder of crook may call upon it to summon 1-6 astral devas. 

In the hands of a lawful good cleric the disruption effect of the crook covers a cone-shaped area 6" long and 2" diameter at its base, and is usable once per round. 

Any evil cleric or creature from the Lower Planes who touches the crook suffers 5-50 points of damage. Any non-lawful good character who uses any of the crook's powers must make a saving throw vs spells on each use or become lawful good. 

Activating the summoning power of the crook subjects the user to a quest to perform some task that furthers the cause of lawful good. 

Anyone who retains possession of the crook for one month or longer loses all interest in sex, and the longer the item is possessed the more serene and imperturbable its owner becomes - after three months he or she loses interest in money, after six months loses interest in family and friends, and if the crook is possessed for a year or more the owner will have no interest in anything external and desire only to to be left alone to spend the rest of his or her life peacefully contemplating the mysteries of the cosmos.