Have more uses for blood

[RNN]

Currently you don't have much reason to want to take a PC's blood - unless you're a hematologist or a Nephezar.

I think it would be interesting if you someone's blood sample to lower the DCs of certain spells. Blood could be used as consumable to scry them easier, or to place a curse on them at a lower dc.  It gives PCs more incentive to guard their precious bodily fluids and for the nefarious to want to take them.

[Egon the Monkey]

I'd love to see more ways to inflict medium term consequences for a PVP defeat. So if you subdue someone, you can have a massive advantage the next time you fight them. As that discourages coming back fullbuffed against someone who beat you previously, as they have blood/a voodoo doll of you/whatever. I thought about suggesting this, but the problem is that even if you make blood be consumed each time you do this, the solution is to yank a lot of blood at once. So it's not a serious limit.

I think a better way of doing it would be to sell "Curse Dolls" or something. Items that you can use on an unresisting/subdued PC. It's then named after them, and you can use the item's special power to apply a dispel effect. Or anything else that's a bit more useful for defence than surprise attacks. This way you pay maybe 1-200 gp up front for the doll, and weight becomes a factor if you stockpile loads.

That way, it's accessible to non-magic PCs, and sparing an enemy doesn't mean letting them plot revenge easily.