Soshisoujuu is an unique Kekkei Genkai that has been passed through the Retsuido Clan for generations. Soshisoujuu's power is based and used with the Suiton(water) element and grants the user control over it in a very unique way. The way that a member of the Retsuido clan uses Soshisoujuu is based on a specific technique and style known as Renkinjutsu. Renkinjutsu is a very in depth and powerful style that is very hard to master. It composes of three different fields of knowledge.
(1)Comprehension - Understanding the inherent structure and properties of the atomic or molecular makeup of a particular material to be transmuted, including the flow and balance of potential and kinetic energy within.
(2)Deconstruction - Using energy to break down the physical structure of the identified material into a more malleable state so as to be easily reshaped into a new form.
(3)Reconstruction - Continuing the flow of energy so as to reform the material into a new shape.
With this knowledge, an user of Soshisoujuu can use their chakra to manipulate and control the very shape, velocity, temperature, and form of water. Having this ability, members of the Retsuido clan can freeze or boil water, opening up the ability of using both Ice and Steam related techniques. Now the extents of using Renkinjutsu with Soshisoujuu is based on how much energy and chakra is used during the time of transmutation. Once this is done, the user can control and water that they come in contact with or have come in contact with within a few moments that the Renkinjutsu chain has been started. The chain follows as such.
Energy and chakra are focused and are used to create an alchemical current → material to be used within the transmutation meets with the energy caused by the reaction → the user controls the energy of the reaction and manipulates the substance that they are transmuting → a change is made within the alchemical structure and a desired end result is left of it.
To perform such a difficult manipulation of energy within a substance would take large amounts of time and focus. To simplify the means of doing this, the founding members of the clan developed a unique way to perform Renkinjutsu, without the need to work through the cycles. This alternate means of performing Renkinjutsu took the form of special circles. These unique circles are known as Hen'i and work almost like seals work for shinobi. A Hen'i can come in many forms but only one is typically used.
The Hen'i used to best use Soshisoujuu with Renkinjutsu:
With the use of this specific Hen'i, a clan member can instantly perform Renkinjutsu through the means of Soshisoujuu. Using Hen'is like this also decrease the amount of energy/chakra needed to perform Renkinjutsu slightly; though performing simply transmutations take very little energy for someone who has trained within the science. Despite the use of this Hen'i the user must still find a way for the current of energy to reach the targeted water. This can be done by means of touching something that also moves or rests against or near water or by directly meeting some targeted water itself. Meaning that the user can clap their hands together to start the current and then touch an object or the element itself, or even another person. As long as there is another connection with the starting current. While performing Renkinjutsu on water by means of Soshisoujuu, it is relatively easy to control the various attributes of water. Being this the amount of chakra required to freeze or boil water and or control it doesn't change unless the subjected amount is clearly different in size or shape.
All water can be used as long as the user can reach the current to it. Also if say an opponent they were fighting against were to use a Suiton based technique; as long as the Soshisoujuu user had a way to connect the Renkinjutsu current to the opponents jutsu, they could use the affects of Soshisoujuu on it. Meaning they could freeze the water of the technique, which could possibly stop the technique, without using the same chakra amount required that the technique itself used. This is because the user is using Soshisoujuu with Renkinjutsu to do so and just because another user uses their chakra to create a technique doesn't mean that the science of Renkinjutsu is also subjected to change to meet it. The chakra required to perform Renkinjutsu doesn't change unless there is clear difference in size/amount or current shape. Also if the user wishes to re-manipulate a body of water after they have already done so, they must break their current and then create a new one for the new manipulation.
Weakness: Now there is no doubt that there is strength within Soshsoujuu but within that strength there is also great weakness. This refers mostly to the Hen'is used to perform Renkinjutsu. Now it is known for a fact that the Hen'i allows the user to transmute instantly once the current has been made, but in truth it is basically the only way in which Retsuido clan members can use Renkinjutsu effectively. Without the Hen'i, using Renkinjutsu is just about useless and without the ability to use Renkinjutsu, the user can't really use Soshisoujuu. Of course this isn't its only weakness. Being that Soshisoujuu is an elemental manipulation kekkei genkai, elemental being the key term, all normal weaknesses of the used elements still apply.
Water ← Earth
Ice ← Fire
Steam ← Wind
Of course the weaknesses of certain elements only apply while the element is in its given form, meaning that if someone was using fire, they wouldn't be able to really over power water jutsu used just because it could become ice.