▰▰▰ Custom Techniques
Custom Techniques are abilities made by a character that is tailored to their unique strengths, abilities and so on, they can range to anything to either build off of what they already have or something else entirely new. These can be anything that the user has access to normally, be it ninjutsu, genjutsu, etc. A custom technique will typically employ anywhere from one to two distinct effects and in some rarer cases even three with given some drawback or weakness. This concept is only but a guideline to what is typical to see in a custom technique. An effect is a very loose term to describe what the jutsu is accomplishing, go wild and see what you create.
• Custom Techniques you design yourself! No real limit outside of the established rules. No further explanations are necessary. Remember, Custom Jutsu follow one to two effects, rare cases three with drawbacks.
▰▰▰ Keystone
Simplified Bit
• Keystones are automatically Variable, either a select few ranks (Example: D-B) or X-Rank. It's a case by case scenario, usually almost all Keystone are X-Rank. A Keystone that spans all ranks as a X-Ranked can achieve 3 effects with no drawback or 4 with a drawback. The drawback is ignored if the keystone only spans a select few ranks.
• Keystones are potent abilities that can be highly adaptable and versatile, they can achieve a wider range of applicable uses easier than a normal custom jutsu
• Stat increases can instead be done at [2] Per rank instead of the universal [1] as per in the rules. However, if a Keystone accomplishes this, it must possess a drawback.
• Keystones are not exempt from the established rules and norms in the guild, they can things to a fault but not outright break them. They will remain a case by case situation.
• Keystone techniques can serve as the parent technique to other custom jutsu. They can impart an effect to derivative customs, usually a specific aspect of a Keystone. Derivative Customs must refer to the parent technique -- these customs are often, but not limited to, variations of the Keystone.
• Derivative Customs of the Keystone ability are not considered a Keystone as such must adhere to the normal rules and must also refer to their parent technique when created.
• Durations for sustained, lingering, etc. style Keystone techniques, the minimal length is much more lax than normal jutsu, with the minimal being 7-10 Posts.
• A Keystone does not consume a Custom slot in any way. They're considered their own separate slot.
• Due to the unique nature of Keystones, they will always be considered a case by case situation when applied for in custom submissions and can be subject to change.
• You can only possess one Keystone at any time barring special circumstances.
Elaboration of Keystone Concept - Please note that the canonical examples used are in spirit of the Anime/Manga, it is just to give an easy example that can translate to our systems.
This is a guideline to the following concept, Keystones. Below will be an explanation and a rough guideline of what these are. Keystones are powerful in what they can accomplish and are too varied to have a set amount of rules with some exceptions.
A special type of specialized technique exists in what can only be described as a signature technique, by default the Ninjutsu and Bloodline classes have access to these types of abilities. Other means of acquiring these also exist such as a bearer of a Forbidden Seal, human sage and those of a specific non-bloodline heritage among other means of obtaining this. A Keystone, or signature technique, is all intents and purposes a Custom Jutsu with a bit of more kick to it, this ability essentially does not take a Custom Slot either and exists on its own.
A Keystone ability is a powerful technique that varies in rank, allowing it to cover multiple ranks as a varied ability. Most will typically cover every possible rank, while some may only touch upon say 2-3 ranks. A Keystone that only covers a select few ranks (ignoring S+) typically can possess more potent abilities than those that do not.
These Jutsu, while powerful and vary heavily in what they can accomplish, cannot bend or warp any currently existing rules that are in place under any circumstances. While they may be powerful, they must adhere to similar standards as any other customs with a bit more leeway.
Normal custom techniques often cover around one to two distinct effects of what they will try to accomplish, three if there is some drawback or barring some special circumstance. Usually these are instantaneous effects that activate without much else going on with them, some are a persistent duration and others have other customs that may combo with it. A Keystone is this and a bit more, they can instead cover a bit more fantastical elements and often will achieve two to three and sometimes even four distinct effects if there's a drawback.
A Keystone are often also highly tuned to being adaptable and variable in both their effect and power to greater emphasize their mark as a signature technique. It should represent that character's unique trait that cannot be replicated through ordinary means, it is their calling card and what stands out as this special technique. Additionally this ability can be further elaborated upon and expanded with any custom techniques that typically come with the Keystone and any other customs slots a person might have.
In the old comparison you may remember that the Keystone was compared to Kamui, a mangekyo sharingan ability that was unique to both Kakashi and Obito in the main series. Kamui and most Mangekyo abilities are quite comparable to exactly what a Keystone is. Kamui was a time-space altering ability that could let the user phase through objects, created a localized warp at a distance, open portals to other places, pocket dimension and such but with only each eye capable of so much at a time.
Last thing I want to imply is that all keystone abilities being capable of ripping up portals, summoning meteors or the like but Kamui is instead an example of what this concept represents.
Rasengan and its many variants can be another example as well. It is instead a varying ability with a powerful effect of shredding whatever it hits, can add an elemental infusion to it and then Naruto went on to create many variants of it that you can scarcely name.