This is my latest story. I'm now working on two stories at the same time! This probably won't end well but hey it helps me deal with my stress, depression, and anxiety. So I'll hopefully write this all properly. If not you all will inform me of any mistakes I make or plot holes I write. But anyways, without further ado, enjoy this new story.

Disclaimer: I don't own Star vs the Forces of Evil or any of its characters.

Summary: Takes place right at the end of the season 3 finale with Marco just being revived. His soul may have returned to his body, but something else hitched a ride along with it. In order to survive, his soul had to merge with what came back with it, and in doing so it changes Marco and his destiny forever. He is no longer really human. He is a monster hybrid. He is an abomination to both his old life and new. He accepts it as his fate and embraces it. He will serve his Queen, King, and Princess. Slightly darker/cold Monster Marco. TomStar progression. Marco pairing currently undetermined.

Chapter 1

Where….where am I? W-what happened? I remember being caught by Meteora….then….Tom saved me and then….I think I saved him? Oh no….I'm….I'm dead….aren't I? Star….Tom….I'm sorry. I'm so sorry….I wasn't strong enough.

Several hours later

What….what is that bright light? Its It's so calming yet powerful. Its….its so safe.

"Marco!"

"Star?" Marco opened his eyes and noticed that he had eyes, he had a body again. He wasn't dead! But….how? Didn't Meteora kill him? Before he could ask anything, both Star and Tom embraced him with tears in their eyes. This brought a smile to the young boy's face and decided that questions could wait until later. Right now, they needed this. They earned it.

"Sorry to cut into this sappy hug fest of yours but, guess what Diaz? We're back!" Immediately, Marco's eyes widened in pure fear as he pushed himself away from Star and Tom and looked around horrified.

"No….please no…." he begged for this to be a nightmare. He begged that he was just hallucinating. He pleaded to whatever cosmic beings there were that he had just imagined that voice. But….

"Marco what's wrong?! What is it?" both Tom and Star asked as they saw their friend panicking for seemingly no reason. He held his head in his hands with tears running down the sides of his face. This was real.

"He...hehe...heheheheHEHEHEHE! AHAHAHAHAHA!" He drew his head back and brought his hands out to his sides as he laughed like a mad man. He then removed the wig on his head and turned to face the young couple, earning a gasp from them both. His eyes were no longer hazel, but a bright purple.

"Monster arm?" asked Star with a horrified look on her face as she tried to approach him only to fall on her hands, still suffering from the exhaustion and injuries from her fight. She barely had enough strength in her arms to keep herself upright, let alone try and help her friend. Tom wasn't fairing much better, he was still suffering from losing so many souls earlier and opening a gate to the Underworld.

"Bingo! Someone give the girl a FUCKING PRIZE! What did she win? How about DEATH BY STRANGULATION!" He grinned maniacally as he turned Marco's right arm into a large purple tentacle and prepared to wring the life out of the young Butterfly. Just as the tentacle was about to reach her throat, it froze in place, with the left arm gripping the base of his tentacle arm. They looked at Marco in surprise and saw that his eyes were slowly shifting between purple and brown, back and forth multiple times.

"Shit….I….I need to get out of here…" Marco quickly reached into his dress and grabbed his scissors before shakily making a portal to a random dimension for away from them. "I'm sorry...I'm so sorry….T-Tom….take care of her, please…." without giving them a chance to reply, he jumped in and closed it behind himself. The last thing he heard before falling unconscious was Tom and Star screaming his name.

Inside of Marco's mind

Ugh…where the hell am I? All I remember is creating a portal and jumping into it before I could hurt Star or Tom…Where did I trap myself now?

You idiot! You ruined everything!

What? Who said that?

I did you fucking idiot!Out of nowhere a giant tentacle with a mouth full of sharp teeth appeared in the darkness. From its expression and tone, it was very clearly angry with him.

Monster arm? Why are you back?! I thought you were too weak to come back! Why can't you leave me alone?! And why can I see you, but I can't see my own body?!

Of course, I'm back you idiot! When Meteora was absorbing your soul, I was forced along for the ride. Her magic tried to absorb me from your soul, but I began feeding off of your soul to fight her magic off and keep my individuality. Unfortunately, because of that very survival tactic I'm now going to lose that individuality! All because you couldn't let me kill your best friends! And to answer your dumbass question, we're in your fucking mind while your body changes.

What the hell are you talking about?! And what's going to happen to me?! You ate part of my soul! And why the hell would I let you kill them?!

Like I said, I ate part of your soul to survive, but when your soul and I were returned back to your body, your soul was incomplete and needed someway to heal or complete itself. Your soul is absorbing me now and changing you as a result. When we finish merging, I will be gone as an entity and be a part of you. This will change you both biologically and psychologically. I tried to kill your pathetic friends to try and break you so that I could try and be the dominant consciousness, but thanks to your annoying determination, that didn't fucking pan out.

So, I'm basically gonna be a freak?! I won't even be fully human anymore? You bastard! If I had a body right now I would be trying to kill you! Wait…who else is back? Who else am I merging with?

Oh so you did notice that little fact? Hehehe…why don't you look next to me and see exactly who else hitched a ride on your soul.

When Marco looked over to where Monster Arm was motioning towards, he immediately panicked, not understanding how they could be in there with him. The being standing right next to Monster Arm with an emotionless look on his face was none other than Toffee, the Immortal Septarian. He was wearing his usual suit and tie but he seemed…different, calmer even.

Hello, young Marco Diaz. Its been a while hasn't it? Since Star killed me, that is. Or rather, she killed the tainted me.

W-what are you talking about? And more importantly, how the hell are you attached to my soul?!

Remember when you punched through my chest after I had finished absorbing Star? Well, as you may have overlooked, punching through my flesh and muscle takes a considerable amount of force, and though you managed it, you didn't come out unscathed. You broke the skin around your knuckles when you broke through my skin and then by pushing your fist through my chest, you forced some of my blood inside of your system, which contained some of my DNA and a portion of my soul. As we speak, my DNA is fusing with the Hydra tentacle's DNA and your DNA to create a Septarian/Hydra/Human hybrid, however at this point, you barely have enough human DNA left to be considered one.

Why? Why is this happening to me?! ….What did I do to deserve this hell?

You decided to be a hero when you didn't know of the consequences. You though that dying was your sacrifice? Don't make me laugh! No…your sacrifice to your friends and to your kind is living. You'll live the rest of your days knowing that you're nothing, but an abomination created by the foolishness of children and the sacrifice of your own humanity. Congratulations Diaz, you're a monster now. Though, even by monster standards, you're more of an abomination than a monster.

Quiet you oversized excuse for an octopus! Just because you already absorbed the Naysaya curse does not excuse you to damage his psyche anymore than it already is! Anyways, Marco it is true that you are now more monster than anything, which isn't necessarily a bad thing. But that's simply something you'll have to realize yourself once you awaken.

Why are you trying to help me? Why are you so different from the Toffee we fought? And how am I supposed to accept myself becoming an abomination?!

Accepting yourself is something you have to figure out on your own, but as for why I seem changed, you can thank your princess for that.

What do you mean?

Back in Mewni

It had been several hours since Marco had disappeared through the portal leading to who knows where and the knights of Mewni where currently attending to the villagers who had been the first victims to Meteora's attack, checking their injures and monitoring them for any immediate lingering side effects from Meteora's dark magic. Tom and Star were currently in a meeting with the Magic High Council and the members of the Marknificent Seven and Star's father.

"Ok, so if I'm understanding you correctly, Moon's MIA somewhere in a random dimension thanks to a Unicorn, you gave Eclipsa the wand in order to defeat Meteora and let her keep the wand and acknowledged her as the rightful queen of Mewni, Meteora was not killed but reverted to a baby, Meteora has gone to find her monster lover Globgor, and to top it all off, Marco's Monster Arm curse returned worse than ever and he disappeared into a strange portal to save you both? Did I get everything?" asked Hekapoo with an exhausted look on her face as she recounted everything Star and Tom had just informed them of that occurred within the last several hours. Both Tom and Star nodded, to her and the rest of the council's dismay.

"Well I think its safe to say that we are pretty much screwed. Maybe not today, but once Eclipsa decides to focus her attention back on the throne after releasing her lover from his crystal prison, and we don't have a fully experienced magical Butterfly to help us in battling them once they come for us. I'll send out clones as soon as possible to every known dimension and have them search for both Moon and Marco. We need to get Moon here and get her to remember who she is as soon as possible, and, if we can, save Marco before its too late." They all nodded in agreement and the members of the Marknificent volunteered to aid in the search as well, seeing as nearly all of them had their own way of crossing through dimensions.

"I don't think we should view Eclipsa as the enemy. Not anymore." Stated Star as she reflected on past events, both recent and historical. The members of the MHC looked at her incredulously while the others in the room simply kept to themselves, wanting to hear her justifications.

"Hear me out ok? Based on what we learned during the trial, to which she answered all questions directed to her truthfully, she isn't really evil. She's just misunderstood and feared unnecessarily as a result. She admitted that she left her throne and arranged husband for a monster, but considering what he seemed like, I don't think she was in the wrong to do so. And though her magic may be considered dark magic by the members of the council, she herself even stated that she never called her chapter in the book evil, to her it was more about the pursuit of knowledge than anything else. She also helped us stop Meteora! If she was really evil, then why didn't she team up with Meteora as soon as she had the wand?" With each point that Star made, the members of the MHC furrowed their brows, seeing no valid arguments to make against them. The members of the Marknificent simply nodded their heads with each point, showing their support in Star's argument for having some faith in Eclipsa, if only for the time being.

"Look, all I'm saying is that she is not exactly what you've made her out to be. And let's not forget about the fact you three helped conspire with a previous king to lock away Eclipsa and her lover, get rid of an innocent child, and replace her just because she was half monster! The only reason the three of you aren't on trial for those crimes is because my mother didn't find it pertinent to do so. But I do! And as soon as the castle is repaired, then all three of you are going on trial for your crimes against the crown!" With that final statement, all three of the members of the MHC eye's widened in worry and were about to try and argue against it until they saw Star's cheeks glow dangerously. She was letting them know there was no room for argument. They were going to pay for their mistakes, like they should have all those years ago.

"Now get out! Do whatever it is you three need to do. The rest of you, go get some rest, tomorrow is only going to be another long day, but hopefully, a less devastating one." With that, everyone bowed to her before leaving. The last person that left closed the door behind them, leaving Tom and Star alone. As soon as that door closed, Star dropped to her knees, no longer able to hold in all of the pain and suffering in her heart. She held herself and sobbed her heart out. Tom walked over to her and held her tight, pressing her head into his chest as he too cried. Both of them crying out in anguish, for she had lost a mother and her closest friend, and Tom had lost the very first person to be his friend. All they had right now was each other, and that was exactly what they needed.

Several weeks later in Eclipsa's castle

It had been several weeks since Eclipsa had found her husband trapped in one of Rhombulus' crystals and ever since then, she has been tending to her child while also trying to figure out how to free her beloved from his prison. Unlike when Moon freed her upper half from the crystal many years ago, the crystal that housed Grobgor was much stronger, powered by not only Rhombulus' magic but also Omnitraxus' and Hekapoo's magic. They must have had to funnel their magic through Rhombulus in order to strengthen the crystal prison so that it could hold Globgor. While being extremely effective and intelligent, Eclipsa couldn't help but also curse them for their ingenuity because it only made it harder for her to free her beloved.

She had gone through the book once Glossaryck had arrived and tried to find any existing spells that could help with her situation but there were none. She had become increasingly frustrated with each failure but every time she took a break and attended to her daughter, her worries dissipated, and her determination would only strengthen. She knew why she was doing this and who she was doing this for. She knew what she wanted, and she knew what she was willing to do to ensure she gets it.

She was currently humming to her daughter while they rested against the crystal imprisoning her love. Her daughter fast asleep against her chest and looking as beautiful as they day she gave birth to her. It was at this moment that Eclipsa sensed a lifeform pass through her wards surrounding the castle. From what the wards informed her, it was a bipedal lifeform, mostly monster in origin, a hybrid, and clearly sentient. It surprised her that he was able to walk through her wards unscathed. They were designed to keep out anyone that would bare her, her daughter, or her husband any ill will. In order for them to be this close to the castle meant they had to be coming for her, but who in the world could fit all those qualifications.

Despite knowing the being had no intention of harming her or her loved ones, she still, as a precaution, prepared her umbrella and hid her daughter behind a protective spell that masked her presence and protected her from harm by reflecting any spells back at the caster and electrocuting anyone that tried physical harm. She floated herself onto the top of Globgor's crystal and shined her spade marks to appear more threatening.

It was several moments before she could hear the footsteps approaching, indicating that he was finally on the same floor as them. She subtly sent out a wave of her magic, reaching all the way to the foreign intruder, analyzing any magic within his body and his soul to see if she could identify him. Her eyes widened in shock when she dipped down into his soul. Sure it was changed and mixed with the remnants of two others but it was undeniably still his.

She then smiled. And then she giggled into her hand before dropping down from the top of the crystal and just in front of the intruder, who was now on one knee with his head down, a tattered cloak covering his entire body, exposing only his light purple legs and long reptilian tail. Letting go of her umbrella, having it just float in the air, Eclipsa grabbed the figure's hood before removing it, revealing his face. His face was narrower than before, and his skin was no longer the light brown it once was but now a faded purple and his eyes glowing green with slits in the middle. His hair, now slicked back in a familiar manner, which suited him rather well now.

"Why, hello there….Marco. You look rather….splendid, now don't you?" She asked as she caressed his cheek with her tainted hands. He looked up at her, looking at her with those bright green eyes of his, filled with nothing but faith and loyalty.

"My Queen."

And done. There goes this chapter of my new story. I wonder how you'll like it as it progresses. Please don't hesitate to review and leave suggestions for what I should do with the story and its characters as it progresses. I already have a pretty solid storyline I want to tell with this but it can change over time. Anyways that'll be it for this chapter.