Chakra Modifiers

Hyourougan (Soldier Provision Pill):

The soldier pill is a special medicine full of proteins and stimulants which allow a ninja to fight straight for three days and nights. The pill will temporarily increase their chakra reserves.

Akimichi Hyourougan Pills:

The Akimichi clan developed three pills to increase their chakra in battle. Ingesting each pill grants the clan member more chakra. By ingesting the third and final pill, the clan member will immediately burn off all the calories within their body turning it into chakra, granting them 100 times their normal strength.

Chakra leechers/consumers:

Various techniques and creatures feast on the chakra found in the body. The Aburame clan's Kikaichuu reside in their host’s body in exchange for their chakra. These bugs will also feast on the chakra of the ninja the clan members fight, reducing their effectiveness. Tayuya's Doki also consume the chakra of their targets. Techniques have also been developed to suck out chakra, such as those used by Akadou Yoroi and Jiroubou. Akatsuki member Hoshigaki Kisame wields Samehada, a sword which also pulls out and consumes chakra.

Jinchuuriki Creation:

"Jinchuuriki" meaning the "power of human sacrifice", are those individuals possessing tailed demons within their bodies. The bijuu are creatures of great power and destruction, and all the ninja nations coveted that power and sought to make it their own as weapons. The hope of Jinchuuriki creation is for the human and the tailed beast to resonate together, thereby granting the human some measure of their immense power and chakra. Each beast appears to interact with their host in unique ways, and grant their host power in different amounts.

Orochimaru's Cursed Seals:

As a form of control, the Sound ninja Orochimaru will place cursed seals on those he wishes to grant more power. The chance of surviving the placing of the cursed seal is one in ten. Once placed the seal will grant the wearer the ability to access their real power. By releasing chakra, the seal becomes active and begins to forcibly pull out more chakra. When the wearer releases the cursed seal to activate the extra chakra, they will lose all their free will permanently over time, transforming the user into Orochimaru's slave.

Hidden Waterfall Hero Water:

This special water from Hidden Waterfall allows a ninja to have a ten-fold increase in chakra for a short period of time. By drinking drops of the water, the ninja of the village could increase their fighting ability to compensate for their villages lack of a strong Kage leader. Unfortunately in exchange for the power, the water also eats away at your life.

Hidden Snow Chakra Control Device:

Hidden Snow developed devices to let them increase and regulate the usage of chakra. This device can suck out the chakra of a captured enemy combatant, eliminating their ability to use jutsu. Elite Snow ninja and Snow leader Dotou also wore armor which enhanced their normal chakra reserves.

Hidden Star Village Meteor:

Approximately 200 years ago, the chakra enhancing meteor struck the Bear Country. Meditating around a meteor grants the ninja a special purple chakra. This chakra is reportedly the users own chakra which has been pulled out through training with the meteor. This chakra will first take the form of feathers which extend from the back of the ninja. These "feathers" resemble that of a peacock. The feathers in turn can be shaped and moved to the ninja's will based upon their seal usage. Because the chakra proves hazardous to the health, few ninja have mastered these techniques, and those that do soon die. The training itself has gone through periods where it was practiced and then forbidden. With the stars eventual destruction, the training and usage of the technique will probably cease.