Zabuza's throat, chest and stomach was full of hateful bile and he had nowhere or right to throw it up. He gulped the lump in his throat again and refocused his efforts on managing his chakra for the exercise the Lord Fourth had given them.
He shook his head and wiped his wet hands on his shirt, no, this was more than a simple exercise, it was what would dictate the end of the war, what would dictate if he was any use to Yagura after all, this was the first thing asked of him that wasn't a mission or order.
Zabuza shelved those thoughts away before they could blossom into doubt, the last thing he need was to not trust himself. The Lord's Fourth's assignment was as simple as they went that Zabuza would have no excuse for failing it but he didn't want to just pass either, he was not the only one with this assignment after all.
Mangetsu stood over on the other side of the ship, both of them stood at the very edge of the ship, not on the deck but on the outward hull where they could plunge into the sea as the warship sailed towards Umehebi. Zabuza couldn't tell or check how Mangetsu was doing as the Mizukage had ordered them into back facing positions, it was a tad humiliating how keenly their rivalry had been read and seen through.
With only his own progress to focus on, Zabuza breathed, raised his hands and went through the hand seals once more; Ox, Snake, Rat, Boar, Dog. Zabuza commanded his chakra to impose his will on the sea as the Mizukage said but as he released it, little more than a bucket of water was seized from the atmosphere, transformed from chakra flowing in his body and attached to his right body in the form of a smooth watery shield that covered him cylindrically.
Zabuza didn't let the jutsu continue as he saw that, instantly cancelling it and restraining himself from roaring at the defiant body of water they were sailing across. He was certain behind him the Lord Fourth was already with Mangetsu, congratulating the boy on completing the simple task of enhancing [Water Release: Water Shield] a paltry D-rank, Genin level jutsu to what will be required to end this war.
He spat out a chip of his own grinded tooth and sought to calm himself with breathing. Zabuza was not lacking in affinity for Water Release, nor was he lacking in chakra or even the talent to successfully cast Ninjutsu, none of those things plagued him except…How can I will the sea to become part of my jutsu?
Zabuza was well aware Ninjutsu specialists oft used their environs to manipulate and enhance the effectiveness of their jutsu. This was all the Mizukage was asking he do, enhance the effectiveness of a paltry D-rank jutsu such that it can defend against the ravaging cannon fire of the two dozen warships they were sailing to meet now.
Ox, Snake, Rat, Boar, Dog! Zabuza performed the technique again but cancelled it the moment it refused to steal water from the sea to offset the cost and enhance its strength. He cursed a slew and prepared himself, Ox, Snake, Rat, Boar, Dog!
He'd only ever thought about strength and he had proven his strength again and again in arenas and even the field of battle so why…why was he failing the true test here?
Zabuza didn't dare console himself with thoughts of how his specialty lay in Kenjutsu and Assassination, that did not matter in the face of his task, it did not matter to the Mizukage for surely anyone with strength would be capable of such a rudimentary task!
Ox, Snake, Rat, Boar, Dog! He merely needed some time more, the sails pushed them quick and fast, they'd be knocking down at Umehebi within hours and yet he felt like he'd need days to uncover the truth to the Mizukage's test.
Another failure…what am I to do? He recalled the Mizukage's demonstration of their objective, floods of water rose to morph around the ship's bow before separating into four shields layered upon themselves like walls within walls. All without a single hand seal.
Zabuza suddenly felt exhausted, his feet wobbled at the edge and forced him to crouch along the edge as he breathed heavy. How am I supposed to do that when…how?
He was far from chakra exhausted fortunately, the swift cancellation of the repetitive failures saved some of the chakra from the already chakra cheap jutsu so he had little to worry about. He glared down at the waving sea, its various tides crashing along the ship as they sailed looked like it wanted to come up, looked like it was lapping up against them, asking for a rope to be thrown out for it to climb up to safety.
But it was the sea and…And it can't come up without breaking the ship or being drawn in by a straw or bucket or something.
Zabuza's thoughts spiralled, he was at the edge of something. He bit his thumbnail and pressed his eyes shut so he could relive the Lord Fourth's demonstration more vividly in his mind. How had he done it? He didn't even stand at the edge like we are he just…no, he didn't need to.
Slowly, Zabuza was realizing the key facets to passing this test. Having an Affinity for a specific Chakra Nature didn't necessarily mean you could command it from any distance without willing it with chakra itself, it only meant the ease at which you could once the necessary chakra component was added was reduced on increased based on your strength.
Yagura-sama is Mizukage for a reason, his strength would be greater but he was still bound by the same rule! Zabuza determined, pushing back to stand as he stared at the sea. His presence, that suffocating power that's always around him is his chakra and only a bit of it needs to touch the sea for his will to become command.
Ox, Snake, Rat, Boar, Dog! This time, before Zabuza released his chakra entirely to the hold of the hand seals formula he poured chakra down the soles of his feet, expelling it till it reached the lapping waters and dissolved within them, "Water Release: Water Shield!"
He felt the change instantly even as the jutsu failed to replicate what the Mizukage had achieved. It sucked on every bit of water and chakra that was his own, forcing it into the formula from determined by the handseals and suddenly his cylindrical [Water Shield] was as high as a he was on the ships edge, except relatively thin and not at all defensible.
A round of applause came from the deck and Zabuza turned to meet the Mizukage and Mangetsu smiling up at him, "Impressive execution, Zabuza, considering you're no Ninjutsu avid. Come, now we refine and bolster what you've both learned."
Zabuza's heart and stomach switched place surely. His doubts quenched as he proudly walked up to the Mizukage, Mangetsu had surely completed the task before him but that was to be expected. Right now, he only cared about the next task.