Clash of the Machina

"Matchup 1: Artemis Jensen versus Aloysius Vyle."
The modulated voice cued the contestants to take their places, though from the looks of the arena they were in, the event was a contest in advertised name only; the friendlier name used in hopes of drawing young blood to what, from the tension, Sen could feel was going to be competition on par with mortal combat.
From his vantage point atop his sister's shoulder, he examined the competitors with the device The Masked Inventor had given him. They had the same function as binoculars, but with them, he was easily able to observe minute details, and even capture and review moments with a press of a button. No camera where he was from was sophisticated to double as much else, especially while being so lightweight.
The first one to his platform was Vyle, a hurried-looking man with a brown suit and hat which shaded out his features, staring intensely at what resembled a clipboard in his hand. He had the air of a man who perpetually expected something terrible to spontaneously happen, whether it was likely to or not.
The other competitor seemed much more confident, though not at all relaxed. Artemis Jensen's blonde hair loosely cascaded around her freckled cheeks and over her forehead, partially concealing a violet headband and only restrained at the back of her head, where it took the form of a mid-length braided ponytail. Despite the elegant look it gave her, Sen somehow knew that her hair was so long because she never considered the time required to have it cut a worthy investment.
Tightening a fist, Artemis rose her wrist up to chest-level, examining it in a manner similar to Vyle's clipboard. They were presumably studying the same things on different devices, as she had no signs of a clipboard on her, and Vyle's wrists held only an analogue watch where Artemis' bracelet was.
Sen scanned lower, examining the girl's attire. She wore a tight-chested top with shoulder straps, a miniskirt proportionally longer than Nia's, and long white stockings. Curiously, she wasn't wearing shoes, having removed them before stepping up to the arena.
Her top was coloured with violet and orange, divided by angled, but mostly vertical intersecting lines which reflected her surroundings like a mirror. The shimmering fabric it was composed of and this separation reminded Sen of a butterfly; an impression which her headband-matching darker violet miniskirt continued.
"She's cute, isn't she?" Nia commented softly, startling the shinobi, "I mean...her face has those little freckles, and her body's not nearly as bulky as mine..."
Sen remembered the magnifying properties of her glasses as she adjusted them. "...she IS cute..." he replied, "...but I wouldn't say she's more attractive than you; just a different kind of attractive. I know you're not comfortable with your body, but it really is nice, Nia. I mean, dad said mom looked just like you at our age, and you know how popular she is...try not to be so hard on yourself."
The demoness bowed her head as she struggled to quell her heartbeat, missing the impressive sight of the ground far beneath each competitor's platform opening. Up from the blackened chasms rose massive shimmering machines, blankly facing one another as they were moved into position. The entire scene filled Sen with awe.
With a light prodding of her neck, he was able to make Nia look up once more. When she did, she gasped at the sight before her. Either the mechanical movements of the doors and platforms had been so silent that they couldn't be heard at a distance, or the apparently glass dome enclosing the competitors nullified sound.
Before Aloysius Vyle stood a rounded brown robot, thickly plated in appearance, with extendable arms ending in three silver claws. The legs of the machine were shorter and thicker, presumably lacking the flexibility of the arms in order to be capable of supporting the bulky body. The legs ended in rounded disks, which presumably aided the robot's balance.
On closer inspection, several lines could be made out along what had appeared to be thick, impermeable armour, suggesting the presence of various hatches. Despite the robot's simple appearance, it was likely filled with various surprises. The ring of red optic sensors dotting the upper half of the machine seemed vaguely possessed of malice, despite their innocuous rounded shape.
Artemis' robot seemed a great deal more graceful. It was significantly taller and more humanoid than her opponent's, and bore a distinctly feminine frame. Golden-coloured plating framed a blank-faced ebony head in a way which made it resemble a helmet. On the head, there were only unlit eyes which were fixed into a determined expression by the form of the metal around them.
Further down, the gold plating returned, making out the form of a tube top above the slender, clearly flexible black multilayer midriff. It was unclear to Sen if this was just for aesthetics or if the gold portions were more durable and rigid, while the black portions were more malleable and focused on absorbing and avoiding impacts.
Beneath the golden reinforcement of the hips, solid-looking, but still effeminate black legs led down to golden "shoes", convincing Sen that his different-durabilities theory had merit. Looking closer, he noticed that both the "top" and the "bottom" of gold had protrusions on them. While any number of things could be kept at the machine's sides, the smooth, wavy shape down where a spine would be on a human presumably housed some high-impact weapon.
The robotic announcer voice came to life once more. "Competitors, prepare for combat," it commanded.
To both travellers' surprise, Artemis' robot knelt in place while Aloysius' top half popped up. As the suited man strode into the center of his machine and engaged a control panel found there, his female adversary tapped the device on her wrist and the strange shape on her machine's back opened, extending a ramp down to the platform on which she stood. With confident strides, Artemis Jensen vanished into the darkness of her machine, and both robots sealed their masters within.
"Both competitors are now ready," the voice declared, "combat will begin now. Round one...COMMENCE!"
With astonishing swiftness, Artemis' machine stepped forward, raising an arm in preparation. Were a human to attack like that, they would be leaving themselves wide open, but Vyle's own robot didn't appear nearly as agile as most humans were.
As if to confirm this suspicion, the brown sphere began to tip over, narrowly avoiding the fist as it fell. It appeared to have shut down in the seconds before it slammed its claws into the arena floor and the lower half of its body sprang out, hammering the feminine machine into a wall.
Sen noticed that the console on which Vyle had stood when boarding was gone. Presumably, it had descended into either the upper or, more likely, lower half of the robot, making its ability to spring open viable in combat. When he looked back to the other machine, its eyes, now glowing bright pink, bore a metal-forged glare of determination.
The sides of the protrusion through which Artemis had boarded split open, and a strange distortion slid out. It wasn't until the pack had resealed that Sen could identify the robot's new accessory. Grey-tinted, yet nearly transparent wings, like that of an insect.
Vyle's own robot wasted no time while this new adaptation was unveiled, and was now nearly upon its opponent. Claw raised, it prepared to rend the middle of the machine in half. The blades on its hands were clearly extremely dangerous, as the floor they had sunk into so easily before was a metal sturdy enough to support the thrashing of titanic machinations.
Nia squeaked and covered her eyes as the attack was carried out. Sometimes, Sen wondered if she was somehow part mouse. Many things about her seemed characteristic of one. As his conscious mind flirted with the idea of his sister bearing mouse features, the combat-oriented subconscious his father had trained in him observed the torso detaching from the legs before the blow actually landed.
The machine's midriff instantly retracted, leaving Vyle slicing at air. Before the brown orb could regain its balance, the hovering torso placed its gold-banded palms on it and shot it back with a glowing light, bouncing it off of the ground. It then dropped back onto its legs, causing the midriff to re-extend.
"Nia, don't look away! This is really good, and it's not like there will be blood!" the shinobi implored, "Aren't you curious about how they pilot these or what they're capable of?"
"I'm...I'm not good with violence," she confessed, "are you sure nobody will get hurt?"
He gave the shoulder he sat on a comforting pat. "Come on, it's just their machines," he replied, "I doubt anyone would enter this if there was danger beyond a few hours of repair work. Enjoy the show!"
The librarian looked up just in time to see the spherical robot fire itself into the feminine one's core, spinning about to land neatly on its feet. She was tempted to re-hide her eyes, but she knew that both she and her brother would regret it if she did. With a deep breath, she watched on.
As Artemis' machine rose to its full height, a shining wave ran along the length of its wings. At once, Vyle's robot seemed to be locked in place, bracing itself against some immense force threatening to crush it. Artemis swiftly ducked low, stepped in and hammered her victim into the air with a rising uppercut, forcing it into the dome's high ceiling with that same force. Not a single sign of damage appeared on the transparent surface.
As the glow began to drain from the wings, it was clear that the effect would soon end. The robot's right hand gripped a handle which had popped up from its hip, and the wings hastily retreated back into their container. As Artemis took her stance, Sen shot up, startling his sister. He knew exactly what was about to happen.
As Vyle's descent began, a beam of solid light shot out from the readied handle, forming a straight blade. The spherical robot flailed and rotated itself  about in the air as the many hatches on its body opened. What followed would surely be nothing resembling a coordinated attack.
Explosives and beams erupted in all directions from the stout machine, the majority of which uselessly struck the dome around them. A few beams seared the edges of Artemis' machine as the one well-aimed salvo of rockets descended on her. To the untrained eye, what followed appeared effortless, but Sen saw a distinct panic in the feminine frame's motion as it rose its blade and ripped through each and every one of the ten or so missiles, reducing their cumulative damage to shrapnel-inflicted scratches on the paint job.
There were no second chances. Dashing forward, the beam blade descended on its dazed prey, leaving only a trail of red-hot molten metal in its wake. The red light faded from Vyle's many eyes as the majority of his machine's upper half slid away, exposing its decimated power core.
A few seconds passed before a ripple Sen hadn't noticed before dissipated from the dome and the synthetic voice came to life once more. "The Victor: Artemis Jensen."
A round of cheers erupted in the crowd, slightly frightening Nia. It appeared that the audience was now audible to the competitors, while the sounds of the fight had been broadcast from speakers around the arena before. Artemis' machine took a graceful bow after replacing its weapon. When she was finished, she returned to her side of the arena, emerged from her robot, and walked out of view with another wave at the crowd.
"That girl is an aspiring swordmaster," Sen commented, arms crossed, "even with mechanical help, no novice could ever perform a counterattack like that, and if a machine somehow could be trusted to entirely, then it wouldn't show physical signs of panic. Those machines must be controlled directly with movements of the body...or at least, hers is when swordwielding."
A strange-looking robot emerged from the middle of the floor, clearly unfit for combat. With its bland grey body and long "arms" ending in harmless-looking digits, it was clearly intended to do only one thing, and that one thing is what it did. Wrapping its limbs around the remains of Vyle's machine, it carefully placed the smaller half on the spot it had originally emerged from, followed by the larger once it was pried open and the man within gently released onto his platform.
With a sigh, Aloysius Vyle watched the remains of his creation descend into whatever area lay in the darkness from which these machines emerged, placing the hat in his hand back on his head before sadly walking offstage.
"Well, Nia?" the shinobi asked, "What do you think? Are you enjoying your venture outside the library so far?"
A tiny smile wavered on the edge of her lips. "...yes."