The law of potential

The magic is based off possible potential, the more the potential the greater the power of the magic powered by it. All things contain potential but things such as grass or insects have very limited scope for exercising impact on the world, this is why most of the magic is based off people. The potential of someone is stored in their blood but whilst it is inside their body it is mainly impossible to access the potential so it must be spilled or the person must die for the potential to be released. When using potential the effect is mainly decided based off the persons mood, in a fight the potential may manifest as something spiked and aggressive, whereas during a calm time it may be less violent. The skill of the user can exert more control based of their power, some do it by careful regulation of their emotions so that the potential comes out as they expect, while others user their own will to work the potential into the desired shape. The potential is only one possibility, so the fate of anything is not determined, if someone with potential dies this may change the possible potential of another as they will now be the one to do the change.  
To use the potential one must be trained by someone knowledgeable to notice what contains potential and how to efficiently access the power, without training the emotion of the person could cause dangerous effects or the potential could be wasted.  
The scientists of Malonar Greybank recently discovered a type of parasite that harvests people’s potential and uses it to grow. The use of this is that the potential within the parasite can be accessed without spilling blood. This results in the person becoming sick and withered and without any will to do anything but basic functions. They also discovered that it is possible to transplant potential into others, first it must be harvested by the parasite then it is transferred into the recipient. This process leaves the subject larger and stronger (much like the changes to the elven people of the Brekka forest) based on the amount of potential, the process can also send the subject mad through visions of the other person and multiple personalities. The changes to the person do seem to vary based off the victim of the potential leech, this implies that the potential takes on something of the person it is attached to, this could affect normal use of potential but further research is required as we have only one user.  
Travellers to other continents have found out of an interesting use fro potential. In some places potential use is not the taboo subject it is here but is practised freely, this is because the main use it of what we would call necromancy. The theory is that when something dies the potential is released in the blood and can be used, so if a practiced user uses the freed potential whilst the blood is in the body but they are dead, or puts more blood in, then they can use the potential to bring back the body. I have observed the strength and how much personality remain of the person depends on the potential in their blood. More blood can also be added to the resurrected body to prolong the life and vigour of the person but it does nothing to change the intelligence or personality which is locked at the start. Though this method some of the kings of that land have maintained power for centuries, living as immortal beings. These lands also make full use of all dead and resurrect anyone they can to serve in the armies of the state if they are soulless, or to continue their lives if they are able.