Hello there.
I don't want to spoil the plot, but by giving some very minor spoilers you would have two possible ways to tackle this.
1) The vengeful aspect of Calistra. The whole region is strong with cults of Rovagug, some old, some new. This cults are very often like your typical cthulhu-lovecraftian cult, hiding just behind the edge of society and doing their sinister stuff. Should they succeed in freeing their god from his prisson in the earth this could spell a very real apocalyptic end to the world, so an Inquisitor fighting the cults of Rovagug in the region wouldn't be out of place.
2) Gnolls are very prolific and widespread in the area, and with gnolls always comes the veneration of Lamashtu. And with Lamashtu comes perversion and the utmost desecration of lust and procreation. Cults of Lamashtu can work in the unterground, too, trying to unterminate the societies of man to bend their lust and desires towards unsavory ends. You could be dispatched to the region to root out this menace.
Both hooks are rather similar, but both work perfectly with the inquisition theme. You could ask your GM if he could accomodate something like this in his campaign. I am gamemastering LoF myself right now, and I really upped Rovagugs involvement because it just felt right and was much fun.
So, good luck and have much fun ;D
