After You and Aang split up with Sokka for the moment Aang dropped you to an Island a bit close to the Eastern Airtemple in the Map. The island has a mountain and it looks deserted but there is an evidence that it was inhabitant before. Now the nature take it's course. You jump down on Appa's saddle.
Aang: I'm getting a weird feeling about this Place Y/N... Are you sure you still want to continue?
Y/N: I'm sure Aang and you need to go the Guru is waiting for you isn't it? So don't go making him wait any longer. Thanks for giving me a lift.
Aang wave and say his Bye to you as you return the gesture. You breath some fresh air and before you take a step you were petrified because a surge of strong Haki stops you dropping your bag and weapon on the sand.
Y/N: H...Haoshoku!?
Then unexpected happens a unfamiliar voice speaks through your mind using the same Haki. You were hearing it very clear as if he was next to you.
???: Welcome Y/N. So you have arrived.
Y/N: Who are you!? How are you able to talk to me in my mind!?
???: Meet me at the top of the Mountain and the explanation you seek I shall give.
The Haki fades and your body feels light again. You recover yourself and picked up the weapon and Bag.
You start climbing the mountain as the road to the top was never easy on the ground you fought aggressive beasts some of their are tamed through Haki and some fight back. Then in the mountains you climb sharp and falling rocks while being attack by some of few buzzard wasp and other predators that roams the air same thing happens.
Y/N: *Exhausted* Just like the island were I grew up!
The sun is about to set and you reach the Top and there is some kind of Temple and in the entrance a Meditating monk with a long staff on his knees sitting as the atmosphere's a little bit strange because despite on top of the mountain the wind is little bit calm . You approach him while your cloak is being blown by the wind.
Monk: Congratulations Y/N. On your first training.
Y/N: Training? I have so many questions! First What are you talking about? Second Who are you!? And Third! Where the fuck are we!?
Tao: My names is Tao I am both ninja and a monk. Half light, Half darkness, I serve Yin and Yang and the balance of all things. Right now the Yin of the Firenation is strong and unstable it threatens the land. I can help you become stronger and help you control your half.
Y/N: You're not making any sense... How did you know me? Why are you willing to teach me yet I'm a stranger to you.
Tao: [Walk towards you.] Because someone spoke to my dream and that someone told me to train you. After knowing who she is. I gladly accept the offer and Wait for the Bison to land at this place. Ever since I gave you the letter I've been waiting for you here.
Y/N: She?
Tao: She calls you her Son isn't she? yet your not related.
Y/N: Fereya! My mother sends you!?
Tao: Yes she wants you to be stronger in order for you to control your other part.
Y/N: My other part... You mean the.
Tao: Dragon, Correct.
Y/N: But the Dragon! Is a Monster inside me! It wants to kill my friends! How is that my self! I don't want to control that thing I want to get rid of it!
Tao: Because your strength both spiritually and Physically are not strong enough to wield it.
Y/N: What?
Tao: The Dragon want's to serve his purpose and become one with its body and yet it cannot because you lack the strength to wield ending it up like a mindless beast. It did happen yes?
Y/N: Yes... Four times actually. But every time I'm in his plane he just stares at me with rage?
Tao: As I said the Dragon is your other self. Both of you share the Emotions and you transform because in rage. You only get to be released if your stronger than him. Merging with him in your current state only brings the Soulless body. Your lucky because you can get out of that state.
Y/N: Then why did he attack me! In the swamp!? If he is me and want's to merge!
Tao: Because the Dragon found a way to Train you himself. In order to be strong sometimes you need to fight the monster inside you. The dragon wants you to be stronger and he did a pretty good job. Didn't he?
Y/N: But how!? How did I have this thing inside me.
Tao: You tell me young One.
Y/N: [Long pause.] I think, back when my mother passed away... She did something as she touched my forehead... That's the only possible explanation I can give.
Tao: Then she awakened your power inside you then... Have I answered all of your questions?
Y/N: I think you did Thank you.
Tao: [Nod.] Now let's get inside we've wasted much time to train.
Y/N: Oh sorry one last question! Where exactly are we?
Tao: This island where the former Dai Li's were being trained. This island bring the challenge for a Dai li to be strong. The beasts the mountain itself and inside of the temple where they fight and the winner will be sent to Basing se as it's protector and the loser will stay and start over.
Y/N: Oh perfect place it is. No wonder the Dai Li's are crazy strong.
Tao: Not as strong were in kyoshi's time. The Dai Li's today forgotten their old ways. I wouldn't blame them many lives has been wasted.
You and Tao enters the Temple and there was a way down being light by the holes in the mountains because of the moon.
Y/N: Is this the part where you're going to Help me control the Dragon.
Tao: No [Sits on a flat rock.] You see the iron walls over there. [Points.] I want you to carry one and destroy them all one by one using your Ryou.
Y/N: Sounds easy enough.
Tao: From the inside.
Y/N: From the inside?
Tao: Your former teacher only teaches you the basic form of Ryou where you can't touch the Enemy but still do damage is it not?
Y/N: Yes Admiral Jeong-jeong taught me I thought it was the highest level.
Tao: No. If you take the Ryou into much stronger level the Haki that Covers your body will become even stronger that it can enter your opponents body and destroy them from the inside.
Y/N: I think I'm familiar with That! What the Dragon and my Teacher Wan shi tong did to me! I felted their attacks from the inside [Touch stomach.]
Tao: Yes. Because they improve their Ryou to the next level. Allowing them to have more power and you can do the same too.
Y/N: Ok but... How is this going to help me control the Dragon?
Tao: First we must put some more strength before we seek the Dragon [Smile.] and believe me this technique will be very handy if you learned it. Now get to work. Remember destroy it from the Inside, Let your Ryou flow not just from you hand but also through the target.
You remove your cloak and Shirt and start doing what he says You lift the giant iron wall. It was very heavy as you sweat hard while carrying it to the Middle.
Y/N: [Panting.] Back to punching again I guess.
You start your training Imbueding your fist with Ryou for hours your fist are not touching the Iron sheet but you keep punching and punching then suddenly you landed your fist punch using your ryou but leaving a small mark at the Iron sheet. You take a break for the meantime.
Tao: Giving up already? [Sips tea.] You have only landed One punch.
Y/N: Shut up! I'm just getting started!
As you start throwing a barrage of punch again with a battle cries trying to land another punch.
Tao: You're straining it again remember your set back. Let the unused Haki flow from your fist to your target.
Another tireless hour of punching you shouted in rage and Haoshoku haki surge as you punch the Iron wall with your Ryou the Iron wall cracks and destroyed from the inside out. Tao smiled and Nod as you fell into your knees due to exhaustion.
Tao: That's it for now. Rest well and you will do the same training until you finished all those irons.
You fell asleep then the next day after you fought beast for food you get back to your training carrying Irons and destroying them with Ryou. You have been getting a hang of the new advance version of Ryou and destroyed quite a lot Iron from the inside out you've felt your Haki is stronger due to your training with Tao. Then crushing the final Iron wall with everything you have with Lightning gauntlets with Ryou.
Tao: Impressive Y/N. As expected you get the hang of it so quick Fereya trained you well.
Y/N: Still I think my Ryou is not strong enough. [Clenched fist with Ryou.]
Tao: Then we will make it stronger.
Tao drop his staff and Imbued his arms with Ryou and Raised it forward to your direction.
Tao: Try to land a direct punch at me Y/N. The next step will be me.
Y/N: Yes Master.
As you punch him the cave tremble and dust and small rocks fall from above but Tao still unfazed steady as a mountain and your fist is not touching his. As he return the impact from your attack you were stepped back from it.
Tao: AGAIN!
You tried again and again as well but Tao keeps blocking your attack. You both do the exercise till sunset and you land a punch on Tao's fist. Tao smiled a bit and had a look of a proud master as he relaxed his Ryou.
Tao: Well done pupil. You have learned the other Advance set of Ryou.
Y/N: I couldn't done it without your help master Tao.
You bow to Tao and he return the gesture. You practices your new Learned technique of Ryou from savage animals to rocks. You take a rest morning comes You and Tao were meditating to relax your mind feeling the breeze of the air which you find it odd because the wind change its vigor as he inhale and exhale.
Tao: For the next training Y/N before facing the Dragon. I wanted to know the results of your days of training. To see if your strong enough to prove yourself to it.
You nod at him and the two of You assume into fighting position then without hesitation you throw the first punch with your arms imbued with Ryou. Tao blocked it with the end of his staff and he parries it smacking you with the other end of his Staff hitting you in the head followed by a back spin kick but you blocked it and give him a hard Right hook knocking him back.
You try to use your advance Kenbunshoku haki and you saw he's going to charge towards you with his staff and he did but you failed to dodge and got scraped because Tao's too quick. Then he swings backward and you kicking it. Both of your Ryou's are clashing then you two engaged in a close combat.
You caught him off guard and gave him a hard lightning headbutt stunning him followed by lightning bending. Tao stand his ground and Redirected the lightning back at you. You were hit by your own attack but it doesn't hurt thanks to your though skin. He delivers a quick jabs at you then driving you back with his Palm thrust.
You two glare at each other with scary eyes and engage again Tao delivers a combo of his staff imbued with Ryou while you were blocking all of it then you grabbed his staff and form a Lightning at your Arm and slam the ground releasing a stream of lightning electrocuting him inside the zone. Then he jumps away from the range of your attack and You charge your arms with Lightning and Ryou and decided to end the Match.
You run towards him with a battlecry but Tao quickly spins his staff above his head then hold his position for the incoming attack. You deliver a strong right punch and Tao counter it with his Staff the Two attacks clashed and Strong winds are blowing from the clash shaking and breaking the entire mountain. You won the clash and sending the staff away from his hands. You two were exhausted then Tao smiled.
Tao: Well done Y/N.