So my D&D players burst in on a ritual sacrifice to Obox-Ob,

Idea one: if any of them are at all philosophical, this will work. Make them eat souls. Eat all that a man was, and ever will be, in the most powerfully metaphysical way. Destroy them utterly.

Idea two: if they aren't, just look for a good aristocrats joke and mine it.

>>52020627
You need to pour centipedes, ants, spiders, and other vermin into the victim's mouth, so that they're eaten from the inside out by Obox-Ob's minions.
Then the PCs have to willingly swallow the vermin which emerge, to gain the power within, and trusting that their patron will not turn on them.

>>52020627
Break out the face cages and life sized plastic rats. Let your players wear them and put a dark sheet over their heads.
Failing that, show them those particular scenes.
Most of what you want is non-mechanical in nature.

>>52020627
Make the Key Skill Endurance. It's not a usual one for rituals, and it'd fit with the amount of punishment an Obyrith should put them through.

>>52025351
>be given power by ingesting a demonic parasite
I like this idea

>>52020627
You should totally confuse the players. Have Obox-Ob send them out to slay demons, break up cults to infernal lords and such.

The players will wonder why, but Obox-Ob wants to bring his rivals and usurpers down a peg, and then you can have them slowly notice that all their virtuous actions are bringing more and more decay.

Reveal a cult of Grazz't amongst the nobility? The peasants don't want to pay their taxes to demon worshippers, and start fomenting rebellion. Meanwhile, cities starve as the farmers don't send grain to the cities.

Help a paladin take out a demonic horde? The ichor seeping from the fiends ensures nothing will grow there. Making it a perfect place for fiendish insects to sprout.