As Chojusen heard more and more of the masked man's rambling, he became increasingly aware of how urgent the situation was. Not only did this psychopath want to destroy his village, which housed more than 100,000 people, it seems he also wanted the Nine-Tails to be a part of an even bigger project. Chojusen couldn't even begin to imagine a project larger than the annihilation of a hidden village.
Even though he became aware of how serious the situation was becoming, Chojusen still couldn't do much. It's not like he could just appear in front of the people in the room and point to the corner, saying "Hey guys, there's a monster hidden over then in space that says he's going to control the Nine-Tails and destroy the village."
Chojusen once again found himself not knowing what to do, so he turn to the system for help. He asked "What should I do to stop this guy from executing his plan?"
[Host has a couple options he can choose from. You could try to learn space locking and just lock the man from leaving his personal dimension; given that your mastery over space is greater than his, it shouldn't be too hard for you to lock him down for a while.
Host could also try to force the man out of his spatial dimension now, which would make his ambush fail spectacularly. However, opting to force him out of his own dimension would be much harder than locking him and if he detects you while you force him out, he will try to kill you; right now you don't stand a chance against this man.
Host's concern over this event calls for a mission!]
[New Mission: Save Minato and Kushina from the masked man's assault. Rewards will be determined by the degree of completion of the mission.]
Even if Chojusen didn't want to help Minato and Kushina survive the masked man's ambush because of the system's reward's, he would still choose to help them because of the off chance that one of the Nine-Tail's attacks could potentially harm or kill his father and brother.
Chojusen instantly chose to learn space locking instead of trying to force the man out of his dimension; It was far more safe that way. It didn't take long for Chojusen to learn space locking as he had plenty of experience "learning" space type skills.
[Host has learned the Skill: Space Locking
Space Locking (Rank C | 0/100): The user manipulates space energy to pause in a targeted area. As proficiency increases, so too does the effectiveness of skill. Current Effect: Stops a Genin level target for up to half a second.]
Chojusen spent all the time he had available, training the Space Locking Skill. He managed to evolve the skill after an two hours of training, and then reached ten percent completion before he heard a woman's scream from outside the enemy's personal dimension. Chojusen knew he would be needed in a couple moments, so he returned to the world outside of the man's personal dimension and checked his new evolved Space Locking Skill.
[Space Locking (Rank A | 10/100): The user commands space particles to come to a complete stop in a targeted area. As proficiency increases, so too does the effectiveness of the skill. Current Effect: Stops a high level Jonin target for up to half an hour, below Jonin level targets can be stopped indefinitely.]
Half an hour should be plenty for Kushina to recover from giving birth, at least the seal should not be as weak as it could be, and Minato would not be completely helpless against the man's ambush. Chojusen just prayed that the man was not higher level than a Jonin.
Just outside of the swirling space, Chojusen appeared and found a woman lying on the bed that had been prepared earlier. She was currently in a lot of pain and would soon give birth. Chojusen only looked at her for a second, before turning back to focus on the swirling space; he would keep a close eye for any movements so he could lock down the space at any time.
After a lot of screaming from Kushina and comforting from Minato to Kushina, a baby's crying voice could be heard. It was at that moment that the swirling space started to spin faster. The exact moment that Chojusen detected a new movement in the swirling space, he used his Space Locking Skill to stop the man from completing his ambush.
Sadly, Chojusen's Space Locking did not hold back the masked man for more than a couple seconds, before the effects of the skill stopped. The good news was that Chojusen's attempt caused the masked man to be stopped for all to see, consequently attacked as soon as he was revealed.
Because Chojusen froze the space containing the masked man, the masked man could not return to his personal dimension to avoid the attacks that came from several Anbu and was moderately injured before gaining control of his body.
The masked man was forced to retreat and Minato became alert. Minato was not expecting an enemy at this time, as his son's birth was a secret event that very few people knew about, and even less people knew that the Nine-Tails' Seal would be at its weakest point during a female Jinchuriki's pregnancy.
A couple seconds after the masked man left, he teleported back into the room and forced Minato to separate from Kushina after an intense, but short, battle. Because his ambush earlier didn't succeed, Naruto — Minato and Kushina's newborn son — did not become a hostage and the masked man could not use him as leverage. So, he had to use his "Kamui" to phase through Minato to get to Kushina, before teleporting away once again.
Chojusen would have liked to stop the masked man from using Kamui to phase through attacks, but he couldn't spam his Space Locking skill and needed to wait half a minute before he could issue out another one. Still, just his attempt of stopping the ambush saved many innocent lives like those of the midwifes that helped Kushina through her labor.
The place where the masked man decided to teleport was still within range of Chojusen's teleportation, so he easily found and teleported to the masked man. Not long after, Minato also teleported there, but Chojusen noticed that Minato had teleported with the help of seals, and was not truly using spatial teleportation.
When Minato arrived to his wife's side, he found that she was being bound by black sealing strings of kanji and the seal for the Nine-Tails was being completely broken. The masked man said "Now come out, Nine-Tails!" and from Kushina's navel a titanic nine-tailed fox with reddish-orange fur came into existence.
After the Nine-Tails came out of Kushina's body, she fell over with no strength. Usually a Jinchuriki would have died from having their tailed-beast extracted, but because she was an Uzumaki with anomalous vitality and life force, she didn't immediately die.
Chojusen didn't want Minato to be distracted from fighting with the masked man and the Nine-Tails, so he teleported next to Kushina and brought her over to his side. All the while his mind and will were fighting to keep him from emptying out the contents of his stomach, as Kuchina's current haggard appearance was almost too much for an untainted Chojusen to handle; she had just gone through a pregnancy and her chest cavity looked like it had been gutted open, to allow the Nine-Tails its freedom. He told Minato "I will take care of your wife, so focus on the village's enemy."
Minato couldn't see him as he was still under the effects of Void Concealment, but given that he had teleported his wife to him before leaving, even if he wasn't an ally, his wife wouldn't be in nearly as much danger with this stranger than she would have been amidst Minato's and the masked man's battlefield.
Chojusen would have preferred to stay back and help Minato fight off the masked man, but Kushina took priority as she would die very soon, if he didn't heal her. Thus, Chojusen teleported Kushina to the mountainside room that she gave birth in and immediately began to manipulate yang energy in accordance with his imagination to create a healing ability.
Even though this was his first time creating a skill for yang energy, it only took him a minute for a skill to be formally recognized by a system prompt.
[Host has learned the Skill: Yang Transfusion
Yang Transfusion (Rank C | 0/100): By transferring yang energy to a target, the user can rapidly recover and even improve the target's vitality and life force. Current effect: Recovers a bit of fatigue.]
Even though the effects of the skill upon creation were sad to behold, Chojusen didn't mind as he knew that in the process of using the skill on Kushina, he would be leveling up the skill dozens of times. The results were as predicted, and after only a minute of healing, Kushina's condition had already stabilized; she wasn't anywhere near her top form, but for the situation, she was at least not under the threat of death.
Chojusen would have liked to stay and treat Kushina a bit more before leaving, but he heard a very loud explosion and even the ground was shaking as if a magnitude eight earthquake had suddenly taken place. Chojusen took this as his cue for Minato needing some help, so he told Kushina that he would be leaving to go help her husband fight off the village's enemy.