Lord of Sorrows

The Lord of Sorrows is one of the most foul Demons to ever set foot on our plane of existence. His carapaced beetle shell covers a body that roils with parasitic worms. Many believe that the Lord of Sorrows long ago ceased to exist, consumed by the foul creatures who wear what remains of his corpse like a suit. However this couldn't be further from the truth, for it is he who is in control, and the worms serve his bidding.
The filthy creatures that use him as a home lay near invisible larva that taint clean water supplies, infecting those unfortunate enough to ingest them. From there the life cycle of the worm begins, as it migrates through its host, making its way to their brain. Within weeks the worm has firmly rooted itself in the victim's nervous system, somehow stimulating old memories and forcing the unfortunate individual to relive all the pain and suffering they have ever experienced. Ultimately the worm consumes any parts of the brain capable of happy memories, leaving nothing but misery behind. Only then is it time for the Lord of Sorrows to appear, and wallow in the despair.