Minato had already returned to his carefree personality when they arrived back to the forest. Yami had nothing to say about this and he just knew that he was not capable of doing something like this. Maybe he also needed to try and control his emotions because it sounded ninja like to him.
" Minato san , can you cut a leaf in two half using only your wind chakra ?"
Yami's sudden question surprised Minato because he did not think that such a small boy would have knowledge about chakra nature transformation.
" I can do that. How do you know about wind nature transformation Yami chan ? "
Minato had a carefree personality so he did not mind satisfying his curiosity by asking Yami directly. Yami coulton not say that he had anime knowledge and insane skills due to system. So he simply lied by saying that he had learnt about shape and nature transformations from an old book inside the Academy library .
" The can you cut a waterfall in half using only wind nature chakra? "
Actually Yami knew already that Minato could do that because he had recieved his experience from the wind affinity copied. He was surprised though because Yami had thought that only Naruto could practice using such an insane method. Geniuses must be different then..
" I can do that but why did you ask that Yami chan? Could it be that you were serious about teaching me a new method to create powerful ninjutsu?"
Minato asked seriously because he could guess that now from Yami's advanced knowledge and questions. Yami just smiled as Minato finally believed him. Actions are reality more convincing than words. Yami made a mental note in his mind.
Minato became cheerful and excited after thinking that he could get new ideas to create ninjutsu. He definitely wont believe that Yami was talking about a S rank jutsu though even if he was strongly hit in his head.
Yami then whispered his simple training plan to Minato which caused him to become speechless then thoughtful then shocked because the simply method could really work.
The plan which Yami told Minato was simple. Just form a rasengan then use a shadow clone to add wind attribute chakra to it slowly until you find the right proportion and the jutsu will naturally form by then. Minato's comprehension power was naturally top class so he could master the optimum proportion easily. He wont need insane number of shadow clones to do the same like Naruto.
Minato did not even think about the fact that how did Yami know about rasengan anyway because it was A rank jutsu and very few people know its existence in first place. He just became extremely focused after creating a shadow clone and formed a basketball sized rasengan on top of his right palm.
Yami just watched from afar as he could feel the strong chakra pulses which became turbulent when the shadow clone started injecting wind chakra into the rasengan. The shadow Clone was another Minato so he immediately lessened the injection pace and soon white spirals started forming around the rasengan.
Minato felt the insane sharp power and lost focus for a moment. Yami felt deep fear as he could feel the sharp power from more than two hundred meters far. Fortunately Minato was a genius to the bone and managed to cancel the flow of chakra before the shape could stabilize a little. Minato wiped off cold sweat from his face as he flashed a smile at Yami to reassure him that everything was okay now. In his eyes Yami was still a child after all. Well he was right as Yami was scared shitless because the power was insane. Especially the loud sound of high speed cutting wind was too scary.
Yami saw that Minato was going to try once again so he could not help but stop him using a loud shout.
" Minato san. Imagine the shape of a large shuriken and use that as reference to shape the wind nature chakra.. " Yami instantly remembered this detail from his anime knowledge and yelled from top of his lungs.
Minato naturally heard the desperation in the voice but he completely disregard it as he suddenly had an enlightened expression and flashed a thumbs up in Yami's direction .
Yami finally relaxed as Minato's genius mind managed to get his point immediately. He wiped off his sweat and could not help stare in Minato's direction with a strange excited smile . He guessed that watching creation of S rank jutsu in front of his eyes was really exciting experience for him and it even surpassed the fear which he was feeling just a second before.
Soon Minato actually completed the jutsu on his second try and after raising his right arm , he threw the large blue white shuriken far away which produced ear spotting sharp noise and exploded after touching a tree .
The large explosion increased in diameter in less than two seconds and completely engulfed the more than 400 meters of the forest area. Even Minato was speechless because the power was far greater than he had expected. His chakra was consumed by a lot but Minato could not help but smile as he was more than satisfied with the new jutsu. Even chakra consumption could be lessened in future after he becomes more familiar with the jutsu.
Just as Minato started thinking about an absurd and long name for the jutsu, Yami came running and excited ruined his plan by saying the name Rasenshuriken . Minato had no choice to accept it because even with his weird naming sense, he found the name cool .
Not a minute later , Yami sensed an oppressive chakra fluctuation coming towards then at fast speed and started feeling the pressure because it was targeting both of them. Minato just stood before him and the pressure completely disappeared. Yami did not waste time and ren away immediately after telling Minato to not disclose about his involvement. Yami did not want unnecessary attention towards him especially of Danzo.