The Eight Gates Technique: The Eight Gates Technique is a powerful secret technique developed by Mitsuyoshi's father after 20 years of practice. Mitsuyoshi passed it on to Mitsukai, who then passed it on to Naruto. However, it is a forbidden technique due to its consumption of the user and the rigorous training required to withstand it.

Gates 1-5: The first five gates allow users to release all their chakra at once, boosting their speed and strength. Intense training is needed to unlock each gate. 

Gate 6: Opening the sixth gate unlocks a new level of power, allowing the user to ignite attacks with high-speed punches and gain a green aura for self-protection.

Vulnerability without Gate 6: Those unable to open the sixth gate, like Chen, are vulnerable to enemy attacks. 

Gate 7: The seventh gate lets the user release blue steam from sweat, allowing them to defeat elite ninjas with just one punch. Recovery depends on physical strength. 

Gate 8 and Death: The eighth gate, called the Death Gate, grants god-like power but costs the user their life. It emits red steam from evaporated blood. 

Seven Days Technique: Shira developed a variation called the Seven Days Technique, which relies on breathing to increase attack power. It doesn't consume life force but instead uses oxygen.

The third level allowed Shira to withstand Rock Lee's attack using the fifth gate. The advantage of this technique is it doesn't require life sacrifice, but oxygen supply is crucial.