By the end of the week, Hanzo's aura is stable and he can hold Ken for 25 minutes. When I step into the Arena and see him training and go to get his attention. I step forward and with what I hope looks like a disappointed expression I say, "You've made solid progress. You can now use Ken to protect yourself from attacks in all directions. I'm not going to lie 25 minutes is halfway decent but I expected a bit better, we will have to work on those aura reserves if you want to have a chance in a real big fight."
Hanzo stands tall, his breathing steady but deep. He doesn't say anything, but I can see the sadness and disappointment in his eyes. To break the tension I start explaining about Ko.
"Ko is a combination of several Nen techniques," I explain as I stand before him, carefully watching for any signs of hesitation. "It combines Ten, Zetsu, Ren, Hatsu, and Gyo to concentrate all of your Nen into one body part. The focus is on that one point the more concentrated the aura, the more powerful that part of your body becomes. But while you're concentrating all of your energy into one place, the rest of your body becomes completely unprotected."
Hanzo listens closely, his gaze intense as he processes the information.
"First, you use Gyo to focus the aura on one body part," I continue. "Then, Zetsu stops the flow of aura to the rest of your body, essentially cutting off the flow of energy everywhere else. Ten is used to ensure that the aura doesn't disperse, while Ren amplifies the energy itself, making that one part extremely powerful. With this technique, that single point of focus can become dozens of times more powerful. But there's a catch."
I pause, letting the weight of the information settle in.
"While Ko is powerful offensively, it leaves you exposed. You're putting all of your energy into one area, which means the rest of your body is completely vulnerable. You need to be extremely careful when using this technique. If someone is faster than you and uses Nen to hit you anywhere you're not using Ko you have a high risk of death."
Hanzo nods slowly, absorbing the information with a focused expression. "So it's a technique of sacrifice. You risk everything for one powerful strike."
"Exactly," I reply. "And that's why Ko is considered an offensive technique. You'll use it when you're certain your strike will land. If you're not careful, the consequences can be disastrous. Let me give an example. You see this big ball, that I was going to use for your Shu training if you ever got up to this stage. This one is 32 Tons and it is very durable now look what my fist going very slow does to it when I use Ko."
I move my hand at a snail's pace charging all of my aura into my palm before hitting the ball. When the ball gets hit it goes flying all the way across the arena. I look at Hanzo and he has stars in his eyes, "WHAT, you barely hit it and it went flying!!"
"Yep, Hanzo imagine what would happen if my fist was going at my maximum speed or even faster using my aura to part the air. It would be dozens of times more powerful than that if I tried hitting it. In fact, Ko is so strong some Nen users employ it as their Hatsu adding conditions onto it."
"Now you give it a try," Hanzo steps forward, his stance steady. I can see the determination in his eyes as he begins the process of focusing his aura. His body begins to hum with energy, the aura around him starting to ripple as he gathers his Nen. The key here is to focus everything on one part of his body, and I watch closely to see how he handles it.
I can feel the pressure building as he attempts to focus his Nen, the air vibrating slightly with the effort. But it's not fully concentrated yet there's still too much dispersing around him. His aura is diffusing, spreading out, and I can tell he's struggling to narrow it down.
"Focus on one part of your body, Hanzo," I say, my voice low but firm. "Pick one spot your fist, your leg, anywhere but concentrate all of your Nen there and hit the steel ball. Don't let your aura leak."
Hanzo breathes deeply, his expression focused. Slowly, his aura begins to shrink, narrowing to a small area around his fist. I see him grit his teeth as the energy builds, his body growing tense with effort. The aura around his fist grows more intense, but the rest of his body is still radiating too much energy. It's not quite right.
"Don't rush it," I advise. "Take your time. Zetsu is the key here. Stop the flow of energy everywhere except the area you want to focus on. Get that under control first."
Hanzo nods, sweat beginning to bead on his brow as he focuses even harder. I can see the changes happening his aura is beginning to contract more, concentrating further into his fist. But I can still sense some of the energy leaking out, and I can feel the strain building in him.
Hanzo's brow is furrowed with concentration, his body tensing as he tries to maintain the focus needed to execute Ko. I watch him closely, my eyes tracking the flow of his aura as it fluctuates around him. A ball of pure Aura is starting to solidify around his fist, but there's still too much of it spreading outward.
"Remember, Hanzo," I say gently, but firmly, "Zetsu is crucial here. You have to control the flow of your aura to stop it from leaking everywhere else. Focus everything into one spot, and don't let it go anywhere else."
Hanzo lets out a slow breath, nodding to himself as he tries again. His aura contracts slightly, gathering around his fist, but the energy around his chest and legs remains too strong. He pushes harder, his expression intense as he tries to cut off the flow in the rest of his body.
"Good, you're making progress," I encourage, stepping closer. "But you're still letting some of it escape. Let your focus get sharper. Use Zetsu to stop the flow from leaking. Picture the aura locking in on that one point."
I see his aura pulse as he attempts to narrow it down even further, but it's a slow process. The air around him hums with the effort, a soft thrum of Aura swirling as he grits his teeth. Sweat drips down his face, but there's a quiet determination in his eyes.
"It's harder than it looks," Hanzo mutters, his voice strained.
I step back, letting him work through it. "Ko takes time to master. It's all about precision and control. You're not just concentrating your energy, you're learning to stop it from dissipating. It's about managing your aura in a way that doesn't just give you power, but keeps it contained."
Hanzo takes a few more deep breaths, the aura around his fist starting to thicken, but it's still too dispersed. I can tell he's frustrated. He's pushing, trying to get it right. I wait a moment before speaking again.
"Don't be so hard on yourself," I say. "Ko isn't something you're going to nail immediately. It takes time. But I know you can do it. You've got the focus. You've just got to learn how to stop the leaks. Once you do that, the power will be there."
Hanzo's gaze shifts from the ball to me, his determination unwavering. "I'll get it right," he replies with quiet resolve.
I nod. "That's the spirit. Keep working on it, Hanzo. You're close."
After a few minutes, he has got the formation of the ball down to a science, "Okay Hanzo, now it's time to work don't he punch."
He swings his fist and the ball flies about halfway across the Arena landing on one of the training dummies.
"Why didn't mine go as far as yours even though I swung harder, faster, and I punched?" Hanzo asks confused.
"Well I have had a lot more training with my Aura and I have an absolutely insane amount of aura reserves I controlled perfectly into that palm strike even though I didn't hit hard my strike is naturally going to go farther than yours if I overload it with a ton more Aura."