Teikouryoku (Power of Resistance)
Before one can treat patients, one needs to protect himself. In real life, medical staff use gloves, masks, etc. But for a Medicla Ninja in a battlefield, thats not pratical. A Medical Ninja must always be aware of becoming a victim of whatever their patient is suffering from so he needs resistance to disease. With this skill you, as a Medical Ninja, increase your natural resistance to most natural diseases and toxins as well as most manmade diseases and poisons, allowing you to threat an infected or poisoned patient with a higher safety. It has no effect on diseases or poisons already affecting you though. This skill, as all others, improves as you grow in power and affords greater resistance to a wider range of diseases and poisons and can become something that you don't even need to focus to achieve.
However, there are limits. This skill will essentially provide a boost to your natural resistance to disease, poison, toxins, acids, alkaline substances, etc but will only basically provide a "shield" of sorts around you. This shield can be overcome, like all others, by overpowering it. This essentially means that you cannot use this to defend from enemy offensive techniques in the misdt of battle.
If you decide to and gain Poison Mastery, allowing you to make your own Custom Poison and mastery that branch of medical arts, this skill will allow you to become immune to regular none custom poisons and to your own poison.
How is it performed?
Now, to do this, you need to focus on your chakra at its core. This, when you look at the chakra circulatory system, is the central spiral network of chakra paths thats surrounds your chakra source, normally located in your abdomen. When you focus on it, you need to visualize a growing yellow and warm aura, spreading from your core, outwards towards your skin. Its this focus and this will that will make your chakra passively aggressive towards pathogens and most natural toxins and infectious diseases. This chakra is invisible to the naked eye and doesn't go beyond the users skin. However, doujutsu might see the aura growing and expanding from the medical ninjas core.
Its this a technique?
Teikouryoku is not a technique, has no chakra cost or is otherwise performed in any way remotely similar to a Jutsu. It is a passive skill, much like diagnosis, taught in the medschool, that gets stronger with time; the more you work with it, the better it will protect you against contagious diseases and poisons.
Are there different stages to its effectiveness?
Yes.
Medical Student: can maintain this skill active for a few minutes, enough to treat a single patient but needs effort and to will it to happen. Its impossible to keep active at all times.
Medical Ninja: the skill can be active for as long as he wishes and he doesn't need to dedicate any kind of mental command or focus for it to work.
Poison Master: Not only is the skill the same as the one for regular medical ninjas as it can protect the user from his own Custom Poisons and similar techniques (for example, toxic/poisonous/venomous elements) at all times.
This is simple, ask any questions and try it out for yourself.
