For the next hour, they solely focused on improving his earthbending. Nathan's now more powerful drive to improve was like fuel poured onto fire, causing his progress in earthbending to surpass the other elements before his hour of training was even up.

Roku once again had him try bending rocks with just his concentration during the last few minutes. All he succeeded in was pushing and pulling it around, but despite the minor accomplishment, Nathan knew it was only a matter of time before he would have rocks circle him like moons circled Jupiter.

"I'm surprised," Roku said as he led him outside the temple. "You've progressed in earthbending much faster than I expected."

"I did promise to exceed your expectations," Nathan replied, smiling and holding his hands behind his head.

Roku smiled in amusement. "Yes. Yes, you did. I hope you'll continue to surpass my expectations with your other elements. In fact, I think you're up for an exercise. Do you see the lake in that direction?"

He looked in the direction Roku pointed and nodded his head. Far, far away from the mountain they were on was a vast, blue lake, shimmering with sunlight.

"We'll begin your waterbending training after you reach it. Don't leave me waiting."

Before Nathan could even ask what he meant by that, Roku immediately sunk into the ground as if it was made of water and closed up the hole, leaving no trace of his presence.

"That… bastard," Nathan said, surprised, impressed, and annoyed at the same time. "Damn it. Did he really just leave me behind? Looks like I'm going down the mountain, then."

Nathan peered down the steep cliff and whistled at the incredibly steep drop. He was hundreds of meters above sea level. He was so high up, the undoubtedly tall trees looked tiny from his position. His heart began to pound in his chest., and despite his fear, he had the urge to jump.

He gulped before taking a deep, calming breath.

'You can do this. Captain America had no issues jumping off of a plane hundreds of meters in the sky and diving into open water without a parachute. That's practically like landing on concrete, but it didn't kill or injure him. I should be able to handle the same thing... I think.'

Nathan began to question himself. While he knew he was technically still a super soldier, he wasn't a full-grown adult like Captain America. That meant his physical development was still incomplete.

'I could just use my earthbending and slide down, but that's still slower than just jumping off… Come on, you even have airbending. Just use it to cushion your fall.'

Knowing that just standing around was reducing his already short training time, he swallowed his fear and jumped off after a running start.

Assisted by gravity, Nathan's body rapidly descended, accelerating towards the ground at a frightening speed.

'HolyshitHolyshitHOLYSHIT!'

For what felt like an eternity, wind battered his face, blowing his hair and clothes back. Immediately realizing that his body's nosedive posture was only helping accelerate his descent, he instead spread his limbs, increasing his drag.

He aimed to land at a small clearing in the middle of the forest while his mind instinctively calculated how much height and time he'd need for a good stop. When he reached the right distance, he pulled his arms back before thrusting them with open palms, creating a constant, powerful gust of compressed air that blew away the debris below. He maintained it until his descent had slowed enough, and when it did, he let go and gracelessly fell to the ground.

"I thought I was gonna die," Nathan gasped like a zombie, his back hunched over as he slumped on the ground. The pumping of his blood resonated in his head.

'Okay… One more goal to add. I gotta get used to skydiving and should probably find an airbender staff in the future. Maybe I could have survived that fall without slowing down that much, but I'm still used to thinking that I'm a fragile human being, not a super soldier.'

Standing up, Nathan dusted off his hands and turned in the direction of the lake.

"It should be in this direction, but it's still pretty far away. About ten miles if my guess is right," he murmured as his heart calmed, peering past the trees. All he could was shrubbery and grass. "Guess I'm running. Time to see how fast I can go while having trees in the way. Movie Cap could run faster than speeding cars in Civil War, so that should be my ballpark goal."

Making up his mind, Nathan took a sprinter's stance and held it for a short moment before explosively kicking off, almost immediately passing multiple trees and crossing dozens of meters in a matter of seconds.

'I'm fast as fuck!' he thought in amazement.

He was worried about crashing into something, but even with trees in his path, he only needed to make slight adjustments in order to maintain his speed, and his eyes had no issue in keeping up with how fast he was going. If there were obstacles he couldn't run past, he just jumped over them.

Nathan had already forgotten the harrowing skydiving experience and was enjoying his nature-made obstacle course.

'Reaching the lake is gonna take more than a few minutes at this rate. Let's go even faster.'

Remembering how Aang could use airbending to boost himself, Nathan began to apply a similar technique. It wasn't something Roku taught him, but he got the idea of how to do it based on what he remembered from the show.

By constantly diverting the air in front of him, he eliminates the air resistance in his path. Next, he slowly began to generate a wind current behind him, boosting his speed. His control over his chi was still shoddy compared to Roku's, so he only began increasing its strength little by little. Eventually, he wasn't even sure how fast he was going anymore, and a big cloud of dust followed him as he blitzed through the forest.

-=-

Nathan slowed to a stop at the lake, leaving two deep trenches on the ground and kicking up a large amount of it into the air.

"Whoo! Finally here!" he said, getting out of the trench. "Ah, goddamnit. I've got dirt in my sandals."

Annoyed, he lifted his feet. While he removed the dirt from his footwear, he looked around for Roku and spotted him nearby, having a hot cup of tea on a platform of solid earth.

'This asshole… He left me behind just to get some tea? Where the hell did he even get it?!'

Noticing his attention, Roku beckoned him over.

"You know, you really could have just gotten us here faster by earthbending or something. Leaving me behind like that was completely unnecessary," Nathan uttered, with a trace of anger in his voice.

Unfazed, Roku calmly sipped on his tea with delight, and Nathan's brow twitched in irritation.

"A fair point, Nathan. However, if I did that, then you wouldn't have been forced to apply your airbending in different ways to solve your problems. And as I said before, using your bending in a variety of situations is one of the best ways to improve your skill in the bending arts. I could have instructed you to jump and use your airbending to soften your fall, but I find this method to be a much more organic and effective way of embedding lessons within your mind."

"Yeah, yeah. I get it. Sorry for letting my anger out on you." Nathan huffed a sigh, looking towards the remarkably beautiful ocean, savoring the soothing scent of the lake.

While Nathan's mind was preoccupied, Roku nodded his head. "Apology accepted, though there really was no need for it. I understand why you reacted that way and, at your age, your emotions can be quite… volatile."

"You can say that again…" Nathan mumbled, his mind only partially paying attention to Roku. "Well, I'm here already. Are gonna we gonna start waterbending or not?"

"As soon as I finish my tea. Take a break for now."

"Ughhh…" Nathan rolled his eyes. "Can I at least try some?"

-=-

"Water is the element of change and adaptation," Roku said as he stared past the lake's surface, their legs partially submerged in the water. "It can be as gentle as a morning dewdrop or as powerful as a raging typhoon. The key to mastering it is understanding its flow, its motion."

Nathan dipped his hand into the lake and watched the water ripple outwards. "Flow… Like going with the current?"

"Precisely. Unlike earthbending, where you have to move a static element, waterbending is about guiding its natural movement. Imagine yourself as a moonbeam dancing on the water's surface."

Wrinkling his nose in confusion, he asked, "A moonbeam? That doesn't sound very fitting."

"Don't underestimate the power of subtlety, Nathan. The moon controls the tides, the most forceful movement of water. But it does so with a gentle pull, not brute force."

"A gentle pull, huh?" Nathan wondered to himself. "Okay. I get it. Be like the moon. But how do I do that?"

"Close your eyes, Nathan. Feel the water around you. Sense its calmness, its constant motion."

Remembering the psychic bending training from before, Nathan did the same thing and concentrated on the water, the cool sensation around his legs. He took a deep breath.

"Now, picture the water as a giant serpent, gracefully weaving through its environment. Imagine yourself moving with that same fluidity."

"I feel it… a soft current, always moving."

"Excellent. Try to gently nudge that current with your mind. Don't fight it, just guide it."

Nathan focused, picturing himself influencing the flow of the water. He concentrated for a moment, then… a small ripple formed on the lake's surface and expanded outwards in a gentle wave.

He breathed a sigh of relief. "I did it."

Roku chuckled. "The training before helped. You succeeded more quickly than your previous attempts on earth. But remember—waterbending is about harmony, not dominance. The more you respect the water's nature, the more it will bend to your will."

"Cool! Can I try making a waterspout?"

"Slow down." Roku held his hand up. "Waterbending takes finesse and practice. Start by feeling the flow, understanding it. Then, you can gradually learn to shape it into more complex forms."

"Bummer. Can I at least try making it dance a little? Like a sea serpent," he said, doing the wave motion with his arms.

"Now you're understanding the spirit of waterbending," Roku said with an amused smile. "A small dance can be just as beautiful as a raging storm. Try once more. This time, lift it from the lake and make it… wiggle a little."

Cracking his neck, Nathan concentrated on the lake's surface. "Prepare yourself, water. I will be your master," he said in a playfully serious tone.

"You do know the water isn't sentient, right?"

"… Can a guy not have a little fun every once in a while?"