Back in my early fanfic days I gave thought to how I'd have continued the series (unaware there already was one planned) and ended up with the kids finally defeating Venger (by, essentially, purifying him) and ending up, via plot device at the second level of the Realm, where Shadow Demon was originally from and had returned to take control of. It was fun trying to work out what extra single weapon they could receive. IIRC I ended up with
Hank - A compass which points to what he needs (even if it's not what he wants). Useful for plots...
Diana - A length of rope which obeys her instructions.
Eric - A sword which grants him great skill, but which is still possessed by the spirit of the first Cavalier to wield it, who was a much more gung ho heroic type (Giving Eric someone new to argue with, it could be amusing or disturbing to his friends if he's the only one who can hear the spirit)
Presto - A book of magic to give him a little more control, but the flipside being he can only use a single spell per day and can't recall spells from days past.
Bobby - That was a tough one, what do you give a Barbarian who already has a club? I gave him a hunting horn to summon up a couple of hellhounds. As the magic is filtered through his perceptions, and his desire for a pet, he ends up with a couple of heckhounds who, when not rending enemeies apart with their slavering jaws, tend to roll on their backs to get their tummies tickled and beg for brimstone biscuits.
Sheila - A lens of rock crystal which shows her to see hidden doors and spot traps etc. IIRC they called it infra vision in the game.