Mastery of Kidō is perhaps one of the most difficult skills a Shinigami can acquire. Even those that are widely regarded as masters of the art, have only just begun the trek up the mountain that awaits them. There are a number of techniques that masters of the art can employ to greatly enhance the effectiveness, power, and scope of their kido, and in time can completely overwhelm an opponent through Kidō prowess alone.
When Mastery reaches a Certain point these advanced abilities become available to the practioners in question; although most of these abilities are almost never seen outside of the Kido Corps with the exception of a few individuals.
These techniques, while incredibly hard in and of themselves are among the first applications members of the infamous Kidō Corps are taught; as they're the first steps nessecary to perfect ones own useage of the art.
Incantation Manipulation: One of the first techniques a practitioner of the art learns is the gradual removal of the incantation required to cast the spell. Many Lieutenants and Captains are easily capable of simply reciting the name of the spell to produce its effect, yet maintain much of its power. There is also the technique of mixing incantations to chain multiple Kido together. This is considered to be among the easiest of all Kidō-improvements, and the Corps scoff at its practise - as most members within the Kidō Corps may easily cast spells in the nineties without even bothering with the full incantation.
- Silent Spells: When one achieves true mastery of the art, they are able to, simply put remove the incantation entirely ---including the name of the spell, without losing a drop of power. This skill is incredibly difficult to obtain, and only those with an extreme level of dedication can achieve. So far only former members of the Kidō Corps have been able to replicate this skill. This ability is noted to be quite common in the Kidō Corps, with this being the first thing Kidō Specialists are instructed to practise; as such - many younger members of the Kidō Corps are capable of casting low-level spells silently, although very few ever manage to nonverbally cast spells above level 40: this ability is not taught anywhere else in the Gotei 13, as its deemed to be too advanced for regular Shinigami, as it would force them to put aside training specifically for this, neglecting the more important points of Shinigami Combat.
Combination Casting: One of the less advanced forms of Kido is the art of combining two or more spells together to create an unique effect; in the Gotei 13 this is typically seen as the mark of a skilled user - the easiest and quite possibly the most efficient way to achieve this by the feat known as double incantation - by combining the incantation of two spells into one long one it becomes easier to mesh the spells together; although they preferably have to be of the same category although true masters of this art is capable of combining both Bakudo and Hadō together for utmost efficiency. It is possible to do this silently as well, although it has only to date been demonstrated in the Valhalla Finale by Hiroya who silently combined Kuyō Shibari, with Sajō Sabaku.
Spell Alteration: This is one of the most commons arts within the Corps; as its an absolute necessity to their craft, due to the natural weaknesses of Kido. Spell Alteration is considered to be the first baby-step towards the advanced branch of magic known to Masters as Henkōdō. Spell Alteration allows the Specialist to change the flow and appearance of their spells, and by that change its effects; through the use of spell alteration - Specialists may freely alternate between various forms of magical combat, turning an offensive spell defensive, or vice versa in a heartbeat - later allowing for them to employ spells, not merely as added techniques, but as weapons.
Quickened Casting: Another technique, is the ability to cast spells rapidly, typically a single spell being cast multiple times in succession. While it is recognized that masters are capable of chaining together different spells, the true application of this skill is being able to fire for example four or five Byakurai, one after another; creating a barrage like effect.
The next stage is the stage that most Kidō experts, specialists and enthusiasts never reach; cause it demands something on a whole other level than the previous stage; and its due to this that those whom do manage to pull this off can dare to hope to one day become a Commander in the Corps.
Motion Manipulation: One skill that is largely overlooked, due to the intensity and high speed aspects of combat, is the manipulation of one's physical motions whilst casting a spell. In many cases casting such spells require often minor movements, a flourish, pointing one's hand at the target, etc. However what masters of the art have begun to discover is that they once they develop this skill, they are able to remove the necessity of such movements. This was first demonstrated in Phantasmagoria: The Struggle, by Unohana-taichou whom was shown to cast all of her spells, without incantation and without motion, only pausing briefly to gather the necessary energy.
"Stacking" Spells: When "Quickened Casting" is employed to the extreme it allows the Kido Master to stack several spells of the same type together to bolster the spell tremendously in power; the previously mentioned Byakurai spells could for example be stacked five times in order to create a spell effect equal to several times the power of a single spell of that type. Additionally, this spell stack appears like a single spell which makes it capable of easily overwhelming an unwary opponent in one fell swoop. This has been noted as being notoriously difficult to achieve.
Spell Mastery: One of most famous trademarks of a true master of Kidō, is that they've become so intimately known with a single spell that they can use it, not as an ordinary technique, or even a spell; but as a weapon - being capable of handling its flow, strength, mass and precision with as impressive skill and ease as that of the best master Swordsmen, handling their favorite blade. To truly master a spell, these sorcerers narrow down their training to include it, once properly mastered - the Master can control, cast and indefinitely maintain the spell, simply by will; spell variations is unnesecary for one who has fully mastered a spell - for their very will alone is enough to change how their spell interacts with the world and its inhabitants, to a specialist whom has achieved Spell Mastery - that single spell holds enough versatility to contest even with most Zanpakutō; as, depending on the skill of the user, it can simultaneously be used in a multitude of different ways, having a single spell work as their primary tool in combat; all while they augment and accentuate it with the rest of their magical arsenal. To be considered as one of the Masters in the Kidō Corps; the ability to use a single spell in this particular manner is a demand.
Just as there exists advanced methods of casting and manipulating Kidō; there are several advanced methods of defending oneself against it ---Kidō is different from most forms of techniques and abilities in that it is usually more like a force of nature; you may shield or evade it, use it to your advantage but it can never be fully controled.
Hanki (反鬼, Reverse Demon): Hanki is perhaps the best known defense method against Kidō, it revolves around neutralizing Kidō by hitting it with another spell of equal spell and power, while originally only possessed by Yoruichi Shihōin it has in later years become integrated into the arsenal of the Kidō Corps as a method of defending themselves against Kidō spells. This version however, cannot stop the movements of an opponent unlike the Shunkō version.
Bōei-mai (防衛舞, "Defense Dance"): An ancient but rare art of Kidō Defense that is used by a few Masters when faced with someone of equal skill; knowing of the illojality that is related to Kidō the Masters will attempt to use immaculate hand-gestures and somatic signs in order to attempt to impose their will on the spell of the opponent; usually to divert, redirect or change it into other spells ---the countless gestures, movements and the elegance ever present is how the technique has gotten its name - Bōei-mai is very tiring for both parties involved both physically and mentally and is thus only used when the situation calls for it; in Bōei-mai injury occurs when one of the opponents does a particular hand-gesture or movement wrong; in essence, when they "misstep" or otherwise lose their footing. The art was appearantly created even before the founding of the Soul Society; in a time where Mastery of Kidō was rare, but with the few masters often having honed their spellcraft since birth. Their skill was thus truly tremendous and in battles of Kidō most spells were capable of ending a battle in a heartbeat, for this reason, Bōei-mai was developed to protect those valuable casters from others of their kind; and in a battle at the time, even a single misstep in this art usually translated to death. For one who defend themselves with Bōei-mai, the power of the opponents spell doesn't matter; all that is relevant is experience, skill and precision.
Practioners with a great level of understanding in Kido also very typically possess deep insight into the exact workings and categorization of the different forms of energy that compose a Spiritual Being; as Kido actually works on those factors
Reiryoku (霊力, Spiritual Power) is the power of one's spiritual energy type when it is aligned with their willpower.
- Spiritrons: The fundamental particles that make up all spiritual things.
- Spiritual Core: As the name implies it is the spiritual center where spiritrons are gathered and stored, generally through consumption of external sources of spiritual power, or absorbed from prolonged exposure to powerful sources or concentrations of spiritual energy. The spiritual core also acts as a capacitor, its size proportional to the will or conviction of the being.
- Spiritual Revolution: When spirirtrons have gathered, they orbit one another, in a similar fashion of electrons in orbit around a neutron. This phenomena describes their tendency to move and flow in any given direction. (characteristics)
- Spiritual Alignment: The actual composition of ones spiritual energy flowing in a particular direction. If Spiritual Revolution is the action of the spiritrons moving than, then Spiritual Alignment is the end result of where they are moving and in what direction. (structure)
- Spiritual Energy Type: Is determined by the alignment of the spiritrons that compose a spiritual body and their latent spiritual reserves. In the majority of circumstances, the spiritrons that compose such a being are not perfectly aligned. Many desires, and wills are competing against each other for supremacy, these imperfections or inner wars within the inner mind, weaken the whole. Generally the stronger the spiritual power, the less imperfections exist. (form)
This list is prone to change over time as new characters make themselves noteworthy