When doing your own magic, rituals, or ancient rituals that call for blood, it all usually requires blood from a specific place. This ring counteracts that necessity and gives you the blood you need when you need it. The ring holds a separate life force whose magic is often used by black magicians and various other sorcerers. This item has also been used to conduct white light magic as well.
One example, there is a ritual for bringing back the dead and it requires the fresh blood of a human, which is arguably the most risky type of blood to need, seek, and use in magic. This item provides you with it without you needing to risk anything.
With this ring, you can also sign magical contacts and pacts with high level spirits and or demons with out needing to give anything in return. This ring will also allow you to place power of any kind on people and objects. It can also be used as a charging piece due to its nature. It can be used to charge items up to 10,000 times. This piece is extremely rare and you will not find another one like it.