Chakra Stones

The congealed chakra resulted from this ability is known by various names; Holy Grail, Philosopher's Stone, Satanic Fossil and most commonly as the Chakra Stones. This leftovers may resemble insignificant rocks that one may find practically everywhere but they are actually more valuable than diamonds due to its hidden power. As its name suggests, it is a tool that grants chakra to its wielder if used correctly.

Usage
The outer layer of Chakra Stone that seems like rock is actually the hardened bloods. It is thin but incredibly durable. As exhibited by Tengen, it took roughly two fully powered Shinreiken blows before breaking apart. Within it contains nothing but the heavily compressed sealed chakra. The crust obstructs the chakra from leaking out but at the same time it also prevents chakra from being extracted. Destroying the shell is not viable as the chakra will be permanently sealed within the crust as soon as it breaks.

The only way to access the imprisoned chakra is to unlock the seal temporary. It is done by injecting chakra onto a few locations following a specific sequences. The unlocking pattern is widely referred as key or code. DNA of the wielders dictates the unlocking code; which means Chakra Stones made from different wielders have different codes. Due to the fact that DNA mutates overtime, even Chakra Stones created from the same individual may have different codes. The unlock code is a secret even to the wielders themselves. Sealing is an easy task but exploiting the Chakra Stones requires extensive decoding works. Wielders usually have the better chance of decoding their own Chakra Stones, after all the code is literally inside them.

Upon entering the correct code, anyone will be able to extract the chakra for five minutes before it automatically locks itself. There are various ways to utilize the sealed chakra. Some people convert the chakra into energies, replenish themselves in the process. Others take advantage of the different nature transformation found in the chakra, performing techniques they otherwise could not. Both aforementioned methods require the user to absorb the chakra into the body, the only difference is while the former convert the absorbed chakra into raw energies, the latter does not.