The Dead Fox and Vixen of Time

Digital art based on my own stock
This picture is still available

There is a rather effective Viking spell to call up this pair, involving the liver of a still-born caribou, the skin of a freshly killed fox and these words: "Koma rauðhærður Herra og Dama!"
 
They will then jump right from your haunted grandfather clock and probably instantly kill you.
You wearing the skin of one of their relatives rightly pisses them off and then some.
If, however you are a trained shaman, you will just raise you wand made of reindeer horn and dipped in the first monthly flow of a virgin and restrain them.
The red-haired Lord and lady will then prophesy, telling you all the bad things that will happen to you in the next ten years. Most of the time they will tell you you won't have ten years, but two if you are very, very lucky before you'll lie groaning on your death-bed, with your kids spitting in your cup of mulled mead.

Frazier and Crowley both agree that they aren't prophesies exactly: by naming the disasters that will befall you the foxes cause them to happen.
Why call them then?
Well, foxes may be sly but they are very literal: like all hunters they believe what they see with their own eyes.
So as a  trained shaman you will wear a mask made to resemble the face of your mortal enemy and those bad and evil things will happen to her or him.
You don't have to paint the masks yourself nowadays, but you can purchase them at www.thatsmyface.com/vmchk/Cust…
The blood of a virgin is bit harder to find, but you might try the Dark net.