Justified
As Darth Maul kneeled before his Master, he could sense uncertainty rippling through the Force from his apprentice, Savage Opress. For the moment, it did not concern him as he felt the piercing gaze of Darth Sidious look him over.
"I am most impressed to see you have survived your injuries," Sidious said, the voice as rough and cracked as Maul remembered.
"I used your training, Master," Maul replied pridefully. "And I have built all this in hopes of returning to your side."
Sidious lifted his head slightly, glancing over at Savage, and Maul saw his yellow eyes beneath the hood. Cold and uncaring, like the distant stars, but yet the gaze was also foretelling of the vast amount of power he possessed as the Dark Lord of the Sith.
"Hmm. How unfortunate that you are attempting to deceive me," Sidious remarked as he turned around.
"Master?" Maul asked, lifting his head as he felt a faint stirring in the Force, a warning of some sort.
"You have become a rival," Sidious declared, spinning back around, hands lifting to his chest before bolts of energy ripped out from the Sith Lord's fingers, tendrils of brilliant blue and purple that danced across Maul's tattooed skin and rippled through his muscles and organs. With a pitiful whine, Maul's mechanical legs convulsed, shorting out.
Savage was instantly at his brother's side, activating his double-bladed lightsaber and placing one end of it between Sidious and Maul, leaving the lightning no choice but to funnel into him. Grunting, he lifted a hand and reached out with the Force, shoving Sidious backwards as he shifted his ground.
Although Savage had expected Sidious to at least be stunned by the blow, he found that, instead, the Sith Lord had used the momentum to flip in mid-air, landing only feet from where he had been standing. Teeth bared, the yellow-and-black Zabrak windmilled his double saber, hoping to either disarm his foe or at least force him to give more ground. Maul, stunned by the lightning and unable to get his legs to work, could only watch as his Master side-stepped Savage's assault, leaning back as he raised a single hand.
Instead of the Force-shove Maul was expecting would happen, Sidious unleashed a stream of lightning at the massive Zabrak, enough to make Savage drop his saber before the throne was ripped from the floor. The thrown chair alone knocked his brother to the ground and Maul snarled, reaching out with the Force to raise the object. An unexpected blast of lightning caught him off-guard and he dropped the chair, screaming in agony as he realized Sidious had temporarily knocked out Savage to deal with him alone.
Shaking off the impact, Savage shoved the throne away as he slowly got up, lightsaber coming to his outstretched hand as he heard the tortured screams of his brother. Igniting the dual blades, he charged, intending to strike with a lightning-quick thrust that would wound or even kill Sidious as the Sith had turned to deal with Maul directly. Before he even got half-way to his target, an unseen force lifted him into the air and he gasped, dropping his saber as he reached for his throat.
A deep throated cackle rose into the air as Sidious turned, advancing towards Savage as Maul struggled to remain conscious, the damage done by the lightning already leaving large burns across his tattooed body. His fingers twitched as he attempted to reach for the saber at his waist, only to find it being thrust into the outstretched hand of his Master who thumbed the activation switch. The light given off by the blade cast the Sith's pale face crimson as another blast of Force lightning ensured that Maul wouldn't be able to come to his brother's aid.
Smoke rising from his body, Maul stared dimly at the weapon as Sidious thrust it into Savage, the glowing crimson tip of the saber appearing between the Zabrak's shoulder blades. Still suspended in mid-air, a mist seemed to rise from his brother's body, emerging from his wounds and then from his eyes, ears, nose, and mouth. As the two Sith watched, Savage's remaining horns shrank and the massive bands of muscle melted away from his body. The last hazy remains of Mother Talzin's magic grew tattered and wispy, then dispersed and vanished, leaving Opress in the shell of his now-oversized armor.
Extinguishing the crimson saber with a click, Sidious retreated a step as Savage fell to the ground, his eyes searching for his brother as a sense of helplessness rose within Maul.
"Brother, I am an unworthy apprentice," Savage muttered softly, his dying breaths coming slow and shallow. "I am not like you. I never was."
Yellow eyes going dull, Savage shuddered as he took a last breath and then lay still, eyes still open and fixed on Maul. Turning his attention to his Master, as Sidious had not blasted him with another stream of lightning yet, Maul felt two different emotions rise within him. Sorrow at the death of his own kin and anger at the one who had trained him. He could channel that anger into power if he could move but he wondered why the death of Savage had brought up a different kind of misery for him. The years spent on Lotho Minor in the depths of madness had hardened him, as had his early training, yet the restoration by Mother Talzin had to be the cause behind his current feelings as he quickly glanced at the corpse of his brother.
"Remember, the first and only reality of the Sith," Sidious remarked as Maul snarled softly, placing a hand on the floor in an attempt to rise. "There can only be two, and you are no longer my apprentice. You have been replaced."
Hearing the words so firmly from his Master confirmed his fears that he had been forgotten about after Obi-Wan Kenobi had bested him in the Theed power core and he had been left to dwell in the darkest corners of the Outer Rim alone and near the brink of death. But despite the isolation, he had found an apprentice of his own and had come back strengthened, making himself a more worthy vessel for the Dark Side to fill with its power. His rage against Kenobi had kept him alive but had also taught him patience, a skill he had not possessed during their duel ten years ago even with him killing the Jedi's master.
Placing both hands on the smooth floor under him, Maul lifted his upper half, still unable to move his legs as he noticed Sidious had not moved from where he stood next to Savage's corpse. A sudden sense of weightlessness enfolded him and he realized, too late, that his Master had seized him with the Force as he was thrown against one of the walls of the palace. Vision swimming, he tried to get up from the blow, only to realize he was now suspended in the air before he was hurled to the floor, smashing into the smooth marble. Then Maul was off the ground again, legs hanging uselessly under him as the sheer amount of lightning had, probably, ruined them beyond any hope of fixing the electrical damage. Smashing back into the wall once more, he tasted blood as his head hit the bricks with a sickening crunch.
Dazed, he blinked as a forgotten rhyme crept into his thoughts, a nagging sing-song bit of poetry that he could no longer remember where he had heard it, or what it meant.
Far above, far above,
We don't know where we'll fall.
Far above, far above,
What once was great is rendered small.
Another stream of lightning tore from his Master's fingers, the blue and purple arcs dancing over his skin as he retreated deep within himself. The Dark Side was his ally and he had survived near-death before . . . except it now came from the hands of the one who had trained him. A weaker part of him wanted to ask for mercy but, he reminded himself as Sidious let him drop to the ground, mercy was a tool of the weak to make others think they were strong. No matter what Mother Talzin had done to him during his reconstruction, he would never reduce himself to begging for something as weak as mercy from a Sith, from his own Master.
"You belong to me," Sidious cackled as the lightning built in intensity. "Your existence is now perfectly meaningless."
Screaming, Maul failed to recognize a wide, triumphant smile slowly appear on his Master's face as Sidious stretched his hands out further. The energy, while severely painful, brought back memories of Maul's early training and he embraced the thoughts, unable to defend himself from a weapon more dangerous to him than a lightsaber. He had learned to cope with the agony back then when he was whole but now it only reminded him of his hatred towards Kenobi. The Jedi had taken his destiny from him and now he was being told he no longer mattered by the one who had seen promise in him from the very beginning.
Despite the agony that flowed through him, Maul managed to use the Force to lift the throne chair from the floor and send it at his Master, leaving himself open to even more damage by the lightning as the brief concentration on his task that distracted him from blocking himself off from the pain of the electrocution. Fortunately for Maul, Sidious stopped his attack to catch the object in mid-air and then send it back at him, barely giving him enough time to brace himself against the floor. The sheer weight of the heavy chair knocked him backwards and he smashed against the thick glass panels that surrounded the throne.
The combined weight of the impact quickly shattered the fragile glass and Maul soon found himself falling backwards, wind rushing past the large burns on his body. Smashing down onto a wide platform several feet below the palace, the sickening sound of bones crunching signaled the end of his life as consciousness quickly left the weakened Zabrak. He might have dealt Kenobi a powerful blow in killing Satine but that single action had brought about his own demise. Thinking back on his actions as his life faded from him, Maul realized he had been wrong to target the Jedi so early after his reconstruction and should have been more patient but none of that mattered now as he closed his eyes.
He had failed his Master so many years ago and had paid for his failure by the loss of his legs. Failing his brother had, ultimately, cost him his own life at the hands of the one he never thought would get involved directly. As Maul took a final breath, he seethed over the fact that Sidious had replaced him with that Sith pretender when he had been trained his whole life to aid the will of the Dark Side.