Project Nemesis is a fan driven website for games that use the One-Roll Engine (like Nemesis, Wild Talents, Reign and Monsters) or Chaosium's Basic Roleplay System (BRP) (like Call of Cthulhu) and the Delta Green setting.
This is more of a terror weapon than anything else, possibly
originating in some long forgotten feud between the cults of Cthulhu
and Cthugha.
The ritualist needs a ruby of at least thumbnail-size and seven sacrificial victims; one male and one female human infant, one male and one female adult human, one male and one female elderly human and finally one male Deep One (anyone with the Innsmouth-gene works fine).
The ruby is heated until it is hot enough to scorch flesh and then quenched in the still beating heart of a each sacrifice while the ritualist chants the proper rites. The sacrifices can be done at separate occasions.
After this is done the ritualist need to carefully heat the ruby one more time, this time over a fire kindled with dried human bones and human body fat. When once again the ruby is hot enough to scorch flesh the ritualist places it in one his own hands and clench it into a fist while whispering the final words of the ritual (BRP: paying 10 MP and a permanent POW). After this the ruby will turn a dull reddish-brown colour and cannot be used again for the ritual.
EFFECT :
A red mark the size of a quarter and with a strange twisting structure appears in the palm of the ritualist. This is the only outward sign of the Crimson Curse. The first time the ritualist makes skin-to-skin contact with someone this person will also receive this same strange mark as the Curse moves from the ritualist to the new victim. The Curse will move from person to person, gathering strength and marking its victims, until finally the ritualist touches the latest victim (the one with the Curse) and the circle is closed. Immediately _all_ victims who have the Mark, except the ritualist, will burst into flame and die in 1d6 agonising rounds.
There are two ways to stop this :
Make sure the latest victim cannot pass on the Curse.
Make sure the ritualist cannot touch the latest victim.
The ritualist can get a general feeling of the whereabouts of the Curse and as the he gets closer (within a mile or two) to the latest victim an unpleasant squirming feeling can be felt in the Marks of all those touched by the Curse. This will increase the closer the ritualist comes to the Curse. If the ritualist is killed the Mark fades over couple of weeks time, otherwise the Mark will remain. Yes, the ritualist touching the dead remains of the latest victim will still set off the Curse, though the dead body cannot transfer the Curse to a new victim.
SANITY COSTS :
2d6 Sanity (Intensity 6 check in The Unnatural) to execute the ritual.
1/1d4 Sanity (Intensity 4 check in Helplessnes) for a victim to become aware of the Curse.
ORE Horror 
