A SP Heart is a body part every SP born creature has. Its function is two fold, both as a power source and a soul. It provides a creature with infinite power and abilities while being completely indestructible. However it also can be considered the creature itself, as every heart is unique and essentially has the "soul" and mind of the creature. In comparison to creatures like Humans, SP Hearts can be considered the brains and main functionality center of the creature.
The heart can survive without a body indefinitely, and can regrow the body around it at any point of time. Within itself, it contains an entrance to a personal reality that a creature can use as a last resort means of escape. Although supposedly impossible, if in a hypothetical situation an SP creature would be vanquished or destroyed, or the reality it is in gets eliminated, the creature will just appear perfectly fine and intact within that reality. From within that reality they can easily choose to go back to the normal reality we're used to.
The heart is almost always a very light blue, perfectly spherical, and always warping and turning. It is always very warm to the touch but also very hard. It also contains all the information unique to its bearer, including personality and appearance.
A heart could be tainted if it originated from outside of SP (i.e. Unknown Entity). In these cases the heart will often be just as powerful, but the essence of the creature would be negative and corrupt. Any tainted heart can be purified however with SP Purification once a creature has been weakened.
Power and Stability
A SP Heart can provide a creature with an infinite amount of power, but since infinity is a rate and not a number, the rate always has room for growth. When a creature experiences tough battles or displays of power, the rate of the infinite power grows. The heart is also responsible for how power can be used, including different kinds of magic or new magic learnt.
The heart is also indestructible using any means (even reality wiping), as its main anchor is not physical. Due to every heart containing a reality, it can be considered a reality within itself, governing its own rules. The presence of the heart in our reality is just one of the many anchors, in this case a physical tether.
Essence and Life
The life provided by the SP Heart is unfortunately inexplainable, even taking into account infinite power. It is speculated that since every heart has its own reality, having life is one of the core rules. Aside from just life and consciousness, the heart provides emotions and immense mental strength. It gives the creatures very important traits such as empathy, sympathy, and willingness to help.