Tyrant Xilian enters the Undertale Universe

The souls in Mettaton's capsule started flickering, their bright colors slowly dying out, Mettaton felt unbearable pain as he felt his body slowly giving out. "A-Asgore wasn't kidding about the pain, it's.. Excrusiating.." He put his hand on his capsule, looking over to see Sans struggling to keep a knocked out Frisk still. "Sans darling..Please escort yourself out of here and go to where Asgore is." Sans looked over, shaking his head. "nah, why would I abandon my post?" His smile lingered, but the exhaustion over his face was evident that he was already tired.

Asgore sat in the destroyed barrier room, looking to the outside world as a small portal opened behind him. Hearing the whooshing sound of an opening portal, he stumbled to turn himself around, aiming his trident. Out of the portal walked Core Frisk, they greeted Asgore, noticing that they were badly wounded. "I see you have still survived up to this point and some of your friends are still fighting for survival." 

Asgore, surprised and confused, asked shakily. "Wh-Who are you? And how did you do that.." Core!Frisk responded. "I am a Frisk, or was a Frisk. I am an outcode, the multiverse's omnipresent observer." Asgore just stared, his confusion staying as he didn't know how to properly respond. Asgore then took a look behind Core Frisk, seeing a luscious landscape full of what looks to be other AUS that were saved. "CLOSE THE PORTAL NOW!" Asgore shouted.

Core Frisk tilted their head as the entire mountain began to shake, the sounds of a clock ticking echoed through the broken barrier room. Core Frisk took no chances and immediately closed their portal, questioning Asgore. "What is the matte-" Asgore cut them off, clearly pissed off. "You may be omnipresent, but you do NOT know the dangers you almost caused! My men have given me intel on the being terrorizing this place that once he feels your soul, you will NEVER be safe!" 

Core Frisk felt a shiver go down their body, it was as if their body, or what made their body, felt a genuine worry. "Then what must we do? How can I protect you?" Asgore stood up, helping himself with the trident. "You can't, we cannot be saved. The beast has already felt our souls for long enough. If we go to your safe haven, we are at risk of having everybody perish." Core Frisk then looked down, unsure of how else to save them, for it was their duty.

"Then may you find peace and tranquility in these dire circumstances.." Core Frisk said, walking back into their portal and back where they came from. Asgore stood there, clenching his arms around his trident. "If death is all that's left on the option table, then why stand here and be an easy target.." Asgore made his way back to the battlefield, noticing that Mettaton was in a critical condition, as well as the humans.

Asgore Dreemur (Weakened)

HP: 2500

ATK: 55

DEF: 80

"The beast, Mettaton must've dealt with him..We might actually have a chance." He jumped from the corridor towards the battlefield, landing with a loud thump, he gritted his teeth as his legs weren't in the greatest of conditions. He walked over to Sans, putting his arm over his shoulder. Sans jumped a little, surprised. "King, what are you doing?"

Mettaton heard Sans talking as he shouted. "K-King?! What are you doing here?! You are in no condition to fight!" Asgore looked at Mettaton Supreme, noticing that the souls had lost their glow. "And you are? I am your King, I am here to protect my Kingdom and the ones who protect it as well." He gave a smile to Mettaton.

Chara began to stand up, vomiting dark red blood through the stitches. "Oh shut up with all the lovey-dovey shit. You are all going to get cut up into ribbons and become a meal to my partner." Frisk's body was starting to twitch as they were regaining consciousness. Asgore threw his trident towards Chara, it being engulfed in a burning bright light. Chara just smiled, jumping up and grabbing ahold of the handle only to spin and chuck it back at speeds of which Asgore's eyes couldn't perceive. The trident was breaking apart just from the speed itself, losing the two, beautiful, crimson side spikes.

Mettaton's thrusters activated in that moment as Sans attempted to stop the trident, he was capable of perceiving such speeds, but his blue magic got overpowered as the blue hue around the trident shattered. Mettaton tried to dilate time one last time, but due to the worn out souls, this merely slowed down the speed by a third. He aimed his arm cannon towards the hurdled breaking trident to attempt blasting it away, however, as his attention was taken away, Frisk had already been mid-lunge towards Mettaton.

As it fully charged, Mettaton unleashed the blast in an attempt to vaporize the trident completely, but Frisk had bit down onto the cannon mid-blast which made him fire it towards the sky. Mettaton cursed out loudly "YOU FUCKING BITCH, HOW DARE YOU- GRAAA-", his cannon getting completely destroyed whilst oil spewed everywhere. Metallic bits and wiring were exposed as Frisk bit down tightly onto the cannon, gulping it down without hesitation. Though the metal parts would kill anybody if attempting to digest them, the chaos energy had completely reshapen their DNA and body structure.

As the trident flew, not being stopped even with Sans's help, it pierced right through his torso. Mettaton stretched his arm out, screaming. "K-KING ASGORE, NO!" Sans muttered to himself in disbelief. "K-King.." The trident's impact had completely exploded Asgore's back, shattering his spine and blowing open his back. Asgore coughed out dark red blood as his organs were now completely exposed.

Chara laughed out loud, as Frisk jumped into the air, landing beside Chara. Sans teleported to where Mettaton was as they both fled away, teleporting to parts of the underground that weren't as destroyed. Chara looked over at Frisk, stretching out their arm. "Well, partner..Are you ready to cause MAYHEM to this timeline over and over?!" Chara summoned what looked to be an ERASE button right in front of Frisk. 

Within the ravine of Mettaton Supreme's ultimate attacks, a bone-like hand gripped the edge, an uneasy pressure emanated out of the ravine as a purple mist started leaking out of it. Chara and Frisk got interrupted as their heads turned to look over at who was coming out the ravine. Their souls started shivering as Chara's scythe weapon started cracking. "What the fuck? There was no scratch on this bloody thing and it's already reaching its limit!" The two's bodies tensed up as they went into defensive positions.

A sudden loud blast of sound erupted from the area, all the debris left on the ground was blown away in a violent explosion of wind as Tyrant Xilian had made his entrance back, his body split in two, barely being kept together. The bones began to slowly merge back together as otherworldly noises were emanating out of him. Under the cloth which covered his face, a green glow was seen sparkling. He was pissed