Thirteen was agitated. She had just lost several of her students right under her nose because of the mist villain. She wasn't particularly good at combat, despite the power of her Quirk, but she couldn't afford a failure like this.
—Class representative, I need you to do something for me,— she addressed Tenya Iida. As the fastest one here, he was the only one with a chance to escape and get reinforcements.
—Tch, do you think I'll just let them— for the third time, Kurogiri was interrupted when a dome of Iron Sand formed around him, trapping him and blocking his sight.
Tendrils of the same material took Uraraka, Shoji, Mina, and Sero, dragging them toward Tetsumaru's position, who remained next to Thirteen on a platform of Satetsu.
Before the astonished gazes of the others, Tetsumaru lifted them into the air, reaching almost to the ceiling and moving them away from immediate danger. But to Thirteen's horror, the boy did not stay with them.
—What are you doing?!— she shouted at her student.
—Aizawa needs help. He won't be able to do it alone— Tetsumaru calmly replied.
—It's dangerous, you can't get involved in that fight!
—I won't, Thirteen-Sensei.
After his words, a large amount of Satetsu sprouted from underground in the form of spikes and dense clouds. The legs of several villains were the target.
—AAARCK!
—AH, ah, wait NOOO!?
—Urkkk!!
Those whose lower limbs were crushed or pierced groaned, screamed, and sobbed. Shigaraki's gaze sharpened, remembering that student with that strange dark particle ability.
He never would have imagined he would have these capabilities, much less this level of... Violence.
—Ugh, what is Tetsumaru doing?— Uraraka groaned upon seeing the blood and tears streaming from the now fallen villains.
For her part, Thirteen was stunned. Hadn't she just given them a lecture on the lethality of their quirks? Had this boy not heard a single word? But then she noticed that, while brutal, perhaps too much so, he hadn't killed a single one of the villains.
Aizawa noticed the same thing and was about to reprimand his student for interfering in this fight, but his words died in his throat. Tetsumaru hadn't entered the fight.
—Well... Technically he stayed back and safe, I guess— Aizawa grumbled to himself. He wasn't going to waste the help he received, but he would make sure to talk to the brat later.
**********
Tetsumaru, just like his other half, was putting on a show worthy of a promising student, but not enough to pose a threat.
He hadn't unleashed as much Iron Sand as he was capable of controlling, barely using enough to almost double what Sasori controlled with the Third Kazekage puppet.
Nor did he demonstrate his tricks when moving the Satetsu in specific and intricate ways, limiting himself to spikes and keeping the rest as a moving wave of sand.
He was only assisting Aizawa.
A strange sensation disrupted the magnetic field that allowed him to move his sand. Tetsumaru moved quickly, evading the mist that was about to swallow him and send him goodness knows where.
—Tetsumaru-kun, come back now!— exclaimed Thirteen with a racing heart. No matter how capable he seemed, he was a student. A student who put himself at risk instead of her, a professional.
What kind of hero would she be if she just stood there, doing nothing?
—Just Tetsumaru, Sensei,— the black-haired boy replied, confusing the heroine for a moment.
Before Thirteen could jump down to support her student, the sand platform that was holding them suspended moved at high speed, tendrils of the same material holding the occupants' feet to prevent accidents.
Just a second later, another Kurogiri portal formed in the spot where they had been positioned a second earlier.
—This is unexpected, but welcome... I can feel when the guy distorts space, thanks to my Magnet element. But it only works in the immediate vicinity of my body or my sand— Tetsumaru thought as he formed a dome around himself to protect against the lightning and projectiles being shot at him by the villains on the ground.
Despite his sneak attack, there were still some who managed to evade his sand and whom Aizawa had not subdued.
The only thing Tetsumaru regretted was not being able to use all the jutsus that the original Kazekage knew.
In exchange for not receiving specific techniques, Tetsumaru received an innate talent for manipulating sand in ways that only Shukaku could imitate, without using a single seal. But while that sounds fantastic, it has a major drawback:
Tetsumaru was not Shukaku and, most importantly, he didn't have his chakra reserves. So, theoretically, he doesn't need Ninjutsu to make a specific movement with his sand, as he could replicate the effect with his mere manipulation.
The counterweight to this benefit is that pure manipulation consumes a lot of chakra. Jutsu exist because it's an efficient way to generate a phenomenon with your chakra.
For example, raising a wall of water with the corresponding seals and adequate chakra mobilization costs much less than simply manipulating water from a river and forming that same wall.
Fortunately, Tetsumaru had the reserves of a Kage, reserves dedicated solely to moving the Iron Sand, Iron Sand that responded very well to his commands, so he found a certain balance.
With that in mind, he fixed his gaze on the weird guy with hands all over his body. The man also evaluated him with narrowed eyes, but Tetsumaru ignored him.
He shifted his attention to the giant chicken that remained motionless by his side.
Shigaraki was about to order something to the Nomu, but Eraser Head appeared at his side and delivered a punch to his chest. At the same time, Tetsumaru sent all the sand that had been chasing the common villains and imprisoned the Nomu.
Out of sight for everyone but him, the sand tried to sneak in between its brain and eyes, intending to paralyze the monster from the inside.
—Nomu!— shouted Shigaraki before Tetsumaru could act.
With a wave of his hand, the Sand dome exploded. Tetsumaru decided it wasn't worth sacrificing his Sensei and moved his last ace up his sleeve.
From beneath Shigaraki, a spear of Satetsu emerged, leaving a large cut on his leg that made him double over in pain, and forming a small shield that molded itself to Aizawa's side just in time to cushion part of the Nomu's blow.
Aizawa grunted from the impact, but thanks to the sand he didn't receive the full force that would have left him breathless at best.
More Satetsu moved in the form of condensed balls, tightening around the Nomu's lower limbs, attempting to restrict its movements and forming small spikes to destabilize it.
—Hnggh! Damn brat... Nomu, kill him now— Shigaraki spat with irritation. At his command, the Nomu changed targets.
Tetsumaru didn't think twice before jumping off his floating platform, which was dismantled when the Nomu jumped up to reach him and slapped it.
There was no Shinobi, with the exception of Gai and some other with Six Paths Mode, who could compete in brute strength with that thing. They simply didn't work that way, and Tetsumaru certainly didn't dare to try his luck.
He formed another cloud of sand and stayed as far away from the Nomu as possible, always moving to avoid its straight-line charges.
He didn't even bother trying to throw a mountain of Satetsu at it. If even Sakura had the strength to send Sasori's Puppet constructions flying, what wouldn't this ugly creature do?
Out of the corner of his eye, he noticed Midoriya, Tsuyu, and Mineta observing the encounter between Aizawa and Shigaraki.
If his memory didn't fail him, the guy with the hands almost killed the little frog girl, but with an Aizawa who hadn't been beaten up by Nomu, Tetsumaru doubted the scene would repeat itself.
For his part, Aizawa was more agitated than he let on. After all, that monster could have broken his bones with a single blow, and that was after he erased its Quirk. If it weren't for his student's sand, he would have come out very badly from that attack.
And now that damned Monster was targeting Tetsumaru.
—What the hell is Thirteen doing?— Aizawa wondered.
Meanwhile, Thirteen kept Kurogiri at bay, who continued his pursuit. Tetsumaru had brought down the platform that kept his classmates and the heroine out of danger. He couldn't concentrate on so many things while he had the Nomu stuck to his ass.
Another gust of wind caused by Nomu's punch almost reached Tetsumaru. The incarnation of the Third Kazekage growled and allowed himself to descend to the ground.
Aizawa, who saw this, became much more alarmed than before.
—Don't just stand there!— he yelled at his student. Had he run out of energy? If so, he was in serious danger.
The Nomu kicked off the ground and shot out in an explosion of debris and dust, barely a blur given the speed it was managing.
—That damn thing, it's like it's using Swift Release— Tetsumaru complained, but he didn't move from his spot.
—Then let's take away its traction— Terumi Mei replied through their bond.
A few meters from the black-haired boy, the Nomu was suddenly shaken by a massive current of water, courtesy of Mei, who had quickly sneaked in from the side.
Although strong, the sudden flow of water managed to hinder its charge, giving Tetsumaru the opportunity to send a current of sand that grabbed its lower limbs again.
But the goal was no longer to immobilize or pierce.
Although the creature was strong, it didn't have any ability to increase its weight. Weight that Tetsumaru could lift with his sand.
The Nomu's feet swapped places with its head, leaving the monster dangling. At that instant, Mei appeared in front of the creature, her hands moving quickly as more sand engulfed Nomu's arms.
With Danzō's teachings in her heart, Mei buried her fingers in the Nomu's eye sockets and gouged out both its eyes, then kicked its chest, moving away in the opposite direction.