Chojusen wanted to make sure that snake-bastard stayed dead, so he used a full powered Space Locking on Orochimaru followed up by a full powered Flame Bullet; he was getting real tired of looking at the snake-man avoid death in such disturbing ways.
The Space Locking might not have done much against Orochimaru when he was in his Hydra Form, but now that he was running on empty, he was totally vulnerable to the Flame Bullet. Needless to say, being blasted by a Flame Bullet put the snake-man out of his misery; not even his corpse remained after the fire died out.
After most of the adrenaline was flushed out of his system, Chojusen took a look around the battlefield to see the damage of his fight with Orochimaru. There were Earth Lances strewn around; many of them broken after being crushed by Manda. Several large stretches of sand had been heated and cooled to glass. There was even a small lake that had formed from the side effects of Chojusen's Water Bullet.
It took this experience for Chojusen to truly understand how absurdly powerful he was; and this was just a measly 1% of his total BASE power, it didn't account for his higher forms of battle! He never got to see the effects of his large scale attacks, since most of the time, when he trained, he fired these attacks of into the void outside his personal dimension.
Chojusen took one last look at the battlefield and teleported back to the Kazekage's Office to catch up with his friends.
…
When Chojusen dealt the final blow to Orochimaru, in some underground hideout, a man with ash-gray hair felt a seal in his body break. The man was Kabuto and the seal that had just shattered was a life monitoring seal that Orochimaru gave Kabuto ever since he became his right hand man.
Kabuto didn't panic after the seal broke, he just calmly got up from where he was stationed and made a trip to one of the rooms in the underground hideout labeled with the kanji for "Heaven Seal." Inside the room there were several naked humans incubating in pods filled with amniotic fluids; the only thing this group of people had in common was a seal mark of three black tomoe.
Kabuto took one of the sleeping humans from the room filled with pods and dragged its body to another room. He drew several strings of kanji in the style of a releasing formation and activated the formation on the Heaven Seal that was placed on the body. From the Heaven Seal an exhausted and broken Orochimaru appeared; Orochimaru's return caused the human he came from to turn into an embalmed corpse.
There were no boundaries Orochimaru wouldn't cross to attain the immortality he craved. Aside from taking over other people's bodies so that his true body lived forever, he also placed Heaven Seals on unsuspecting victims with a bit of his soul to ensure that he would continue living even if his true body died for some reason.
Souls were connected until they left to the pure world as they called it in this universe, so Orochimaru had the memories of his true body fighting with Chojusen when he woke up from one of the Heaven Seals. Just the thought of fighting with Chojusen again caused him to shed a layer of cold sweat.
After awakening he had Kabuto heal him and made a change to his plans. Originally he went to the Hidden Sand Village to propose of an alliance to strike at the Hidden Leaf Village during their Chunin Exam, but the Kazekage decline any and all negotiations. He didn't want to leave the Kazekage alive to warn the Hidden Leaf so he attacked Rasa.
From there he had his encounter with Chojusen and died. Now he would have to change his plans or cancel them completely. In any case healing his soul took precedence over anything else for now, so he focused on that first.
…
After Chojusen returned to the Kazekage's office he was tackled and knocked to the floor by Karin. She started crying over him and said "I thought you died when Gaara's dad came back alone!"
Chojusen gave her a hug and said "Calm down. Look at me, I don't even have a scratch."
Karin took a closer look and indeed, he didn't have a scratch. When Rasa saw that Chojusen was perfectly fine after that insane large scale fight, he was also surprised; but he knew that Chojusen was an anomaly that ignored space and time, so his surprise was a bit damped.
Only he knew just how ridiculous the fight against the snake-man had been as he had almost died to Orochimaru and had been there to witness the first half of Chojusen's battle. Karin, Gaara, Kankuro, and Temari could not possibly comprehend to power Chojusen had to come back from facing the snake-man uninjured.
Chojusen playing it off as if the fight was nothing special did nothing to help them understand and they quickly forgot this event to enjoy their time together, before it was time for Chojusen and Karin to go back to the Hidden Leaf Village. As always, Chojusen cooked a grand feast that he, Karin, and Gaara's family enjoyed, before leaving with Karin.
Back at home, Chojusen was allowed to spend the week leading up to the Chunin Exams as he liked. His power was literally bordering on the Immortal level so body training would not help him out that much. He found out that his unlimited growth — granted by the system — did not come without its points of bottlenecks, some time around half a year ago, when his power and speed reached 99.99 Billion points.
In the system's words [Host has reached the bottleneck for the Immortal Level, to get past this, host must have his energy surpass 50 Billion points and completely grasp one Law Principle.]
At that time Chojusen had no idea what the system meant by "completely grasp," so the system clarified with [Host has learned how to use Law Principles, but he has yet to actually master them. As soon as Host completely masters the use of a Law Principle the rest of the Law Principles will be clear for the host to learn and master as well.]
Ever since his body reached to defining line for immortality, no amount of gravity training or body refinement would improve his speed or power, so his main body joined his clones in improving his energy stat.
He wouldn't be reaching the 50 Billion mark for energy any time soon and adding his main body to train with his clones during the week he had would not amount to much — according to the Law of Diminishing Returns.
So Chojusen chose to help train and or teach his friends some tricks to help them succeed in the Chunin Exams.
He started out with Karin and Ino since they were his girlfriends. Both of the girls were naturally gifted with regards to chakra control so Chojusen taught them air walking; both as a method for training their control and as a valuable skill by itself. Karin was used to Chojusen's crazy tricks, but Ino was floored at the sight of her boyfriend literally flying.
Choji, his brother, was the next person on his list to help. Being his brother as well as an Akimichi allowed Chojusen to know the most — with regards to fighting — about Choji out of all the people he talked to. Chojusen first tested Choji's prowess and was surprised to see that he was around the level of High Chunin; when he used all his power and skills.
For his brother, Chojusen helped him improve his physique with a gravity seal to prepare his body for Butterfly Sage Mode as soon as his energy reached the standard of Jonin; at that point Chojusen would be able help him train Sage Mode and the other various Sage Forms. He made Minato the scapegoat once again to present Choji with the Gravity Seal.
For the rest of his friends, Chojusen did something for each of them. Sakura was as gifted with Chakra Control as Ino and she had affinity for Water, so Chojusen taught her his Water Healing Skill. Apparently, she was also born to be a medical ninja.
Chojusen taught Kiba how to better produce synergy with his beast companion Akamaru, by sharing his experiences with Chokogo. While he never used her up to this point in battle, he had trained with Chokogo several times in the past in case he ever found someone powerful enough to force him to use her on top of his Fiendgod Butterfly Sage Mode.
Shino was a complete outlier to Chojusen as he had no idea how to help Shino improve. But Shino was still a good friend, so Chojusen just asked him what he would most like to improve before the Chunin Exams. Shino's answer "Speed."
Chojusen could only think of teaching him how to use either a lightning coating or wind coating. Shino prefered the wind coating, so Chojusen taught him to apply the skill to his clothes, weapons, and skin.
Shikamaru didn't want any help, but he wasn't a prick about it. He told Chojusen "It's too bothersome to train, now that I have a week off." Chojusen reciprocated by "coincidentally" leaving behind his method for using Illusions. Chojusen knew Shikamaru was a strategist, so using genjutsu should be helpful to him.