Tyrant Xilian enters the Undertale Universe

Sans, the laziest monster of the underground has now changed to be more serious about his role as a judge and has even taken the time to improve himself physically, spiritually and mentally. 

Now we move to Mettatons perspective..

Mettaton was limping, his body worn out beyond its limits. Each step he took felt like the circuits in his body broke and his wires snapped. The further he walked down the hallways, the more his body started fixing itself. "Huh?" Said Mettaton, confused as all the pain he had felt just moments ago were fading away. "Oh my, is this some sort of miracle?" Nailix responded "Indeed, for it is my gift to you." Mettaton got startled, jumping back, seeing the Angel Nailix. "O-OH, h-hello darling!~" Said Mettaton, lifting one foot up and waving with his hand embarrassed.

"Also, what do you mean by gift?" Nailix, answered his question "It is my gift to you, for you not only sacrificed yourself for the underground, but you were also willing to save those who couldn't defend themselves." Nailix stood up from his seat, walking down, every one of his steps echoing. "I have brought you all here to improve yourselves, you will all be getting a different path, but as you all take those different paths, you will also intertwine those paths to help one another." 

Mettaton nodded, already eager to begin, he didn't have that many questions. "Ooooh, will there be an audience with the path?~" Nailix just bluntly responded with a hard "No." This almost killed Mettaton's good mood, but he had to deal with the reality of the situation. "However, the angels will always look down upon you, so you can count that as an audience." Mettaton raised his head, his good mood immediately returning.

"What must I do now?" Questioned Mettaton, as Nailix pointed over to the side. Mettaton looked over and saw what looked to be a smithing table, though it wasn't there physically, it was an apparition. "What-" Nailix cut him off. "You will improve your brainpower, constructing parts of yourself to improve your current body. You are already there spiritually and are willing to take risks, but your time will not be taken away sooner than it should." Mettaton was confused, even after getting a concrete explanation of what his purpose would be. 

Nailix, being very patient, just explained it to him once more. "You will take the job of your maker, you will create and replace parts of yourself to further improve your capabilities." Mettaton thought about this momentarily, getting flashbacks of Alphys' horrendous demise, it was engraved into him and he couldn't forget it. "I don't.. I don't want to remember that moment ever again.. I wish I never did!" 

Nailix flicked his finger. "Wish granted, the memory of you losing your maker has now forever been removed from your memory. As a bonus, I instead filled your thoughts with all the positive stuff you both did together, to reminisce in peace." Mettaton remained silent in that moment, taking in a deep breath and just falling to his knees. "Th..Thank you darling." 

They both remained silent for a couple of minutes as Nailix awaited patiently. "Alright..Alright.. I am ready to take the role of my maker, Alphys." Nailix smiled, suddenly being in front of Mettaton "You will undergo the same process as your friend, Sans." Mettaton looked up in awe. "Same..Process?" Four Nailix's then formed around Mettaton, speaking in unity.

Mettaton got lifted into the air, his body glowing a bright white color as his appearance got a drastic change.

Mettaton now stood at a height of 14ft, his sub-par metallic parts being changed to the finest angel forged metals. He looked bulkier than before, but that didn't slow him down, it only made him that much more intimidating in battle. He had 4 faces, each one with a different emotion, that being Sadness, Anger, Joy and Fear. 4 rings intertwined on his head, creating a sophisticated spinning wheel, in the middle of all those rings was what looked to be an energy cell which powered his whole being. His wings at the back sprouted, the tips of the wings having angelic feathers whilst the rest of the wings were made out of royal angelic metal alloys. In the center of his torso were crystals at the shape of a heart, these crystals being made of a holy prism. 

Mettaton EX, Mechanised Perfection

HP: ???

ATK: ???

DEF:???

*Reborn with an improved database and body.

Mettaton's face was that of Sadness as he spoke in a much more clearer tone now, his voice having four different voices from the rest of the emotions. "I am forever grateful for this gift. I will use this power for the good of not just my people, but others as well.." Nailix, put his hands on his shoulder, still a tad bit taller than Mettaton. "You will now be known as the Mechanised Perfection, for you are not just my perfection, but my fathers as well." He embraced Mettaton, patting his back. "Now, you must fulfill your duties and go with your friends, help others and improve yourself as well."

Mettaton vanished in that moment, moving at speeds of which could not be comprehended to the mortal eye.