[POV: 3rd Person]
[Scene: Naka River]
[Track Change: Deltarune Ch. 1 'Quiet Autumn']
Fugaku had led Asriel and Renjiro to the Naka River, the river itself was very clean and clear. No pollution like what Renjiro would see in his world or what Asriel would see in Waterfall. The waterfront was very well taken care of.
Following Fugaku, they arrived at a small dock on the river. On the left side was a sign with some ropes attached. The sign warned against swimming due to fish nets in the water, looking along the attached rope Renjiro saw two red buoys, likely where the net was placed.
"Alright then, it seems we have this place to ourselves for now. Asriel, you were the one who wanted to learn [Fire Release], correct?" Fugaku turned to ask.
"Yes sir." Asriel said.
"Alright then, first you need to learn the Rules of [Fire Release]."
[Track Change: Deltarune Ch. 2 'It's Pronounced "Rules"']
"First and foremost, [Fire Release] is a primarily Offense based Nature Transformation. A few techniques can be used for Defense or Sealing, but [Fire Release] is primarily used for it's destructive properties.
Second, [Fire Release] Ninjutsu are typically created by kneading Chakra in the chest before expelling the Ninjutsu through the mouth. This is usually done to prevent backfires from [Fire Release] harming the User or their Allies. The reason comes down to control, directional control.
If I made a campfire now, which direction would the flame and smoke move?" Fugaku asked.
"In the direction of the Wind, right?" Asriel said.
"Correct, now imagine that the Wind is blowing in your face, or toward your Allies, what would happen if you used [Fire Release] in that scenario?"
Asriel's face turned slightly grim before replying,
"It would harm myself or others unintentionally."
"Yes, Fire needs Fuel, Heat, and Oxygen to burn. Chakra is the Fuel, [Fire Nature Transformation] creates Heat, and Wind carries Oxygen.
Wind pushes extra Oxygen into [Fire Release] increasing it's power, but also altering it's direction. This is why most [Fire Release] Ninjutsu are expelled from the mouth, the Airflow created by exhaling can influence and somewhat control the initial direction of a [Fire Release] Ninjutsu.
This can prevent backfiring on the User, but once the Ninjutsu has been cast, the User needs to manipulate it further to ensure it hits it's Target and not an Ally. I will take more about Wind later.
Third, [Fire Release] Chakra can be channeled into weapons, if channeled into a sword it can be used to increase the blade's temperature, increasing the cutting ability of flesh, but likely won't change much against other things with out heating to absurd temperatures, which is infeasible in many situations.
For example, if I want to cut a [Earth Release: Earth Style Wall] with a sword, I wouldn't use [Fire Release] Chakra on my blade, Earth's thermal conductivity is low, it takes temperatures of over 800 degrees Celsius (1500 Fahrenheit) to cut just Stone. Very inefficient to put it lightly. In this situation using Neutral Attribute Chakra for all around enhancement would be better, with Wind being better at cutting and Lightning for piercing.
Fourth, how [Fire Release] reacts to other elements. In the Academy most kids learn a very basic version of this. Fire counters Wind, Wind counters Lightning, Lightning counters Earth, Earth counters Water, and Water counters Fire. This is a very basic explanation that is not sufficient to understand how the elements interact. While most of this is true, they are true for specific things and not as a general Rock-Paper-Scissors Interaction.
For example, no matter how powerful the [Wind Release] Ninjutsu, it can never overpower even a basic [Fire Release] Ninjutsu because the Oxygen in the Wind makes it burn more. However a significantly more powerful [Fire Release] can overpower a weaker [Water Release] by evaporating its Water.
Now, what do suppose happens when a C-rank [Great Fireball Technique] comes into conflict with a B-rank [Phoenix Sage Fire Technique]?" Fugaku asked Asriel in a quizzing manner.
Asriel replied "The B-rank Jutsu wins?"
"Not just wins, it increases in strength by absorbing the [Great Fireball Technique]. It would likely approach Upper B-rank power. But rank is not all that matters in this case. In the case of using the same nature, there is power and there is skill. A user of [Fire Release] with a better grasp on [Fire Nature Chakra Transformation] can still win using a C-rank Ninjutsu against a B-rank Ninjutsu.
This is especially exaggerated in the Uchiha's records of Madara's combat ability. It was said that Madara's B-rank [Great Fire Annihilation] could reach the power of an S-rank Ninjutsu due to his exceptional strength in [Fire Nature Chakra Transformation] and Chakra Reserves."
"That does seem very exaggerated, but it's true." Renjiro interrupted. "Madara awakened the Mangekyo and later the Eternal Mangekyo by transplanting his brother's Mangekyo. His chakra reserves likely rivaled Hashirama if they were able to fight for three days. His strength in [Fire Release] is likely ranked number one in the history of the shinobi world."
"Yes, Unfortunately the Uchiha haven't gained another genius like him since. Whether it was because they were talented but fell short, or if they were plucked before they could bloom. Thankfully Minato is now Hokage and is helping us bridge them gap with the village. We've gotten side-tracked.
Asriel, I will now demonstrate [Fire Release: Great Fireball Technique], then I will explain the concept and the hand seals."
[Snake → Ram → Monkey → Boar → Horse → Tiger]
Fugaku completed the six seals in a bit under two seconds, took a deep breath and spit out a fireball over 5 meters in diameter over the river.
"Amazing..." Asriel said in a hushed whisper full of awe.
"That was just a basic demonstration. A fireball of that size is considered passing in our clan. If you want to be acknowledged for your mastery, a fireball of 10 meters is a baseline. I can create a fireball of 12 meters without straining myself.
Creation of a fireball of that size requires not only skill in [Fire Nature Chakra Transformation] but also incredible Chakra control and decent reserves. That's why it is seen as our clan's coming of age technique.
You aren't an Uchiha ninja if you cannot reach a level of competence in our most basic [Fire Release] as it is the gateway to many of our other techniques. In fact, most [Fire Release] Ninjutsu use the Great Fireball as a base.
The [Phoenix Sage Fire Technique] is essentially a volley of many smaller [Great Fireball Technique] used for controlling movement or for spread damage. The [Fire Dragon Flame Bullet] is a [Great Fireball Technique] used with [Shape Transformation] to resemble the shape of a dragon. Skilled users can create multiple dragons and use them for area denial or just a straight forward attack. However this requires even more Chakra and high level control.
Let's start with practicing the hand seals." Fugaku finished speaking.
After a bit of practice with the hand seals, Asriel was able to cast his first [Great Fireball Technique], it measured only about half a meter (20in). Fugaku said it was a decent first attempt and that most don't even get that on their first try.
About an hour later Asriel's [Great Fireball Technique] was now 4 meters in size. Fugaku was shocked at Asriel's progress. Asriel said it was mostly his experience with using [Fire Magic] that allowed him to progress more quickly.
Honestly, you and Renjiro likely have the best natures for your ideas of Ninjutsu fusion. Both Water and Fire are very versatile, [Shape Transformation] allows innovation with the only limit being your imagination and your magic's abilities.
Speaking of, do you mind explaining your magic to me?"