Today is the start of his chakra mode training, for the moment he could only do one thing and that is battle training. Saito asked Yamato for his assistance in this regard. Yamato crated a wood clone to fight against Saito.
The two of them where facing each other, Saito and Yamato's clone where ready and as soon as Yamato gave the starting signal both Saito and the clone rushed at each other. Saito already activated his chakra mode and slowly started activating his second phase. With Saito's current power and speed Yamato didn't need to hold back and used his full power to clash with Saito.
The way Yamato fought was peculiar he uses his wood release to increase the damage of his attacks and also lock down his opponent.
Saito launched a lightning speed punch but Yamato dodged and using his wood release a bunch of wood stakes jumped from the ground directly at Saito, Saito used his fortified strength and the wood stakes to propel himself in the air, and using the same technique he used to dodge Orochimaru's attack midair he lunched a Kunai near Yamato and used a steel wire to move towards Yamato ready to deliver a kick.
Yamato saw Saito coming straight towards him created a turtle like barrier made of wood. Saito's attack landed but the fortified wood didn't budge. Before jumping away from the turtle barrier Saito used a smoke bomb and while retreating stuck a bunch of explosive tags on the shell. After moving away he activated the tags, after which a huge explosion occurred, Saito knew that it wasn't enough. And surely before the smoke cleared up a water dragon came directly towards Saito.
Saito using his speed avoided the attack while lunching a barrage of shuriken towards the smoke. Alarmed he felt a little movement in the ground beneath and as fast as could jumped away. And truly in the place he stood Yamato suddenly appeared.
Saito started to sweat, Yamato didn't use some of his more powerful ninjutsus and Saito was barely avoiding his attacks.
Saito decided to increase his power even further, increasing the speed of his blood flow to the limit he knew that his body could handle the strain. After increasing his power to the limit he could feel his body screaming in pain but he knew that if he didn't learn to ignore the pain he will never break his limit. And just as he was going to make his move he felt a weird feeling like everything around him was clearer and he could catch every little detail of his surroundings. And surely he caught a glimpse of Yamato who was preparing another jutsu without much effort he threw a barrage of kunais and shuriken stopping Yamato from completing his own jutsu. And at with a crazy speed he appeared next to Yamato using his elbow to deliver an attack directly to his ribs. That attack had all of Saito's power behind it and the damage done was horrifying. A huge hole appeared in the clone directly destroying it. Saito was happy with his success, but that didn't last long because soon he was hit with a splitting headache and blood started coming from his nose. Directly after that he lost consciousness.
Yamato was astonished at the power displayed by Saito in that last minute, but when he saw Saito falling to the ground he jumped directly to catch him. After checking his pulse he directly took him to the hospital.
The doctors diagnostic left him in shock, apparently Saito's brain was overloaded, luckily he didn't suffer from any physical damage, and he was just tired.
One day latter Saito finally opened his eyes. His head hurt and he felt as if he had nails stuck in his skull. Slowly, he started using his Chakra mode to heal his body and after that concentrated on his head. Yamato soon entered the room.
Yamato: "How are you feeling?"
Saito: "Good after waking up my head hurt but with a little healing the pain disappeared."
Yamato nodded but his face looked serious.
Yamato: "Can you tell me what happened before you lost consciousness."
Saito told Yamato every detail about what he experienced.
Yamato: "The reason you fainted is because you overloaded your brain. Thankfully you didn't suffer any permanent damage. From now on I forbid you from using that technique. Until you learn controlling your chakra mode with more efficiency."
Saito knew that Yamato was right if his body wasn't constantly healing he would have become paralyzed or worst braindead. He understood what happened by increasing blood flow beyond a certain limit his brain started to work at an accelerated rate. Increasing in the process his sensory abilities and also removing the limiter on his body. He knew how dangerous it was and for the moment he could only try to master his own technique step by step.
After confirming that everything was alright he was discharged from the hospital. He decided to take a break for today, do some sightseen and try some of his favorite dishes.
Saito didn't have such relaxed day. He felt that it wasn't bad to relax from time to time. At night he returned home and after a bath a directly fell asleep.
Next day he felt full of energy and he had an idea of how to work on his chakra mode.
After going to the training grounds he created two shadow clones and each one of them started using the 1st phase chakra mode and try to maintain it as long as possible without losing chakra. Minimizing his chakra usage of this technique will help him increase the time he can maintain the chakra mode and also will help him reduce the strain on his body. That days training was a cycle of him using chakra mode and resting by the end of the day he managed to keep chakra mode active for two hours straight. The following day he started the second part of his training. His chakra mode increase his regenerative powers and if he concentrate on healing an area he could heal it almost instantly. Today he will try to enhance his chakra mode to increase his body's healing rate to monstrous levels making almost. Using the shadow clones he began another session of hard work. By the end of the day he finally managed to use it on his whole body after that he activated his 2nd phase and as he expected he could increase the speed of his blood without receiving any damage the strength he could display further increased but he still didn't dare increasing the blood flow to increase his brain activity.