Recently I came across gosshiku-hime-wa-yami-san amazing fanfic "Fire Safety is Important at a Blood Moon Ball". It was such an amazing fanfic that it inspired me to write my own Tomco fanfic with the blood moon au! Not only that, I also found shittyloops (tumblr) badass demon!Marco design. [ shittyloops tumblr com/tagged/demon%21marco] So about the fanfic, this will be a story about Marco and Tom standing under the blood moon light and Marco becoming a demon. I hope you would like this story! Enjoy reading~

He can't believe that Star honestly left him to go to the Blood Moon Ball with her demon ex-boyfriend, Tom. He just can't trust that guy, not only because he's Star ex, but he's also a demon for God sake! He's from the Underworld, not some rainbow paradise. He can't help but worry about Star, though he also knows that she could take care of herself. However, that's about fighting, this is about dating. That demon doesn't seem like the type of guy who would change easily and would be bad for Star to date again. Besides it's more fun to stay here at home.

He sighed loudly and sunk deeper in his chair, sulking about the fact that Star chose her ex above her friend. He grabbed a handful of nachos to stuff them in his mouth while listening to Mexican music. With a mouthful he held his fingers up, pretending he has a ton of fun.

"I'll have my own Blood Moon Ball in Star's bedroom. Where it's always funnnn..."

He even wore his special black tuxedo for this evening. Now Star's not here, it all feels meaningless. He planned to have a lot of fun without Star, so he could tell her what she missed out. However, in reality it's impossible to have fun without his best friend. He glanced quickly at the Blood Moon, wondering if Star was having fun without him.

"..."

He looked back in front of him and grabbed another handful of nachos, stuffing his mouth full with it. He should really stop worrying about Star. It's not like anything could go wrong in at a demon prom… It's not like anything could go wrong, since Star has her wand with her to protect herself. Besides, if Tom really changed for Star, then he could protect her in case some other demon wants to hurt Star… Yeah, these thoughts are totally reassuring to him. Totally.

"Blood moon tonight."

Did Marco hear that right? He looked around, but saw no one standing close to him, yet he heard a voice. He glanced at a portrait of an old sea captain. It couldn't come from him, could it? He quickly glanced at his nachos. Maybe he ate too much from them or they are expired. Or he just felt so lonely without Star that he's hearing things. Well, whatever it might be, he will just shrug it off and continue with chewing his nachos.

"The moon of lovers."

"Okay, now I clearly heard it," Marco thought and was truly weirded out by it as he jumped out of his seat. He looked suspiciously at the sea captain's portrait again. What does it even mean by 'the moon of lovers'? Marco runs his eyes over Tom's bell and the hammer. Could it be some kind of evil spell to trick Star? Something that will make Star love Tom? Or maybe there's some other dark magic going on? Who knows what Tom might be planning. By all means, his gut tells him something will happen and he doesn't want to find out what that would be.

As he looked how the bell's red crescent moon ornament shimmers, he remembered again, it was a demon prom in the Underworld. Not a great place a human should walk around. So he decided to go in a Día de Muertos disguise. Well, he basically just wears a skull with a mustache mask, but that should be enough. At least he hopes that would fool the demons. Once he put the mask on, he gazed at the bell again.

Three full seconds of air in, then a deep breath out. He knows Star wouldn't be happy about this, but his gut tells him to go to Star. He needs to take her away from the ball. As he slowly took the bell and the hammer in his hand, he closed his eyes, rethinking if he was making the right choice. Once his eyes opened, they were full of determination. "This is for Star's sake," he thought as he hit the hammer against the bell.

xxx

"Whoa, wait a second. Are you getting angry?"

Star asked, slightly surprised, not that it was a total surprise since its Tom after all. She knew he still has a short temper and-

"No." Tom denied while glaring at Star.

And he's a liar as well. Him frowning in anger wasn't convincing his 'no' at all, which only annoyed Star more. She doesn't want to deal with Tom's temper, so she will leave him be. Maybe he could cool down that way, though that might be difficult for a fire demon.

"Look, you do you, Boo. I'm gonna go get a drink."

As Star walked towards the bubbling punch bowl, Tom kept petting his bunny till the fur goes straight up. He can't help but feel so frustrated about Star's behavior. He knows he needs to do his best to win her over, but not only did she not accept his spider hair thing. She also didn't appreciate what he does for her. He kept everything low-key for her, which made the rest of the guests bored. As a prince, that's quite a sacrifice. Actually he doesn't care about his image as the demon prince of the Underworld, if that means having Star back as his girlfriend. He even hired a life coach, which made other demons look at him like he lost his mind or with pitiful eyes. Of course they still behave well-mannered when they face him if they consider their lives as precious.

"Hm? ...Oh no, he doesn't."

Tom noticed some demon offering Star to dance, no way in hell he will make that happen. She's his date for tonight after all.

xxx

So this was a demon prom huh. Marco actually expected it to be more...gore? Or at least more horrifying. For now it reminds him of some Halloween party. Maybe the Underworld wasn't so half as bad as he thought it would be. Even though those are real demons that are walking around, instead of children in costumes.

He shook his head and slapped his hands on his cheeks. He shouldn't get distracted so easily. He needs to find Star and get away. A human isn't supposed to be here after all, so he needs to be quick.

While searching for Star, he bumped into someone… or something? For a split second he was sure he saw something black in front of him. Like some black fire? Or black energy. He wasn't sure what it was, but when he bumped into it, it gave him a grim feeling around his stomach. However, that awful feeling disappeared in an instant, like it never happened before. Now, in front of him stands a girl with long red-orange hair who seems to be around his age. She wore a short white dress with sleeves that goes wider to the end. She also has a white mask on the top of her head, it looked like a shape of an animal's head, but he couldn't clearly see what kind. The young girl, who surprisingly looks very human, smiled sweetly to him as she walked around him out of curiosity.

"You know, humans are like food to demons."

She whispered in his ears and smirked at him, while her eyes are glowing red. She took a step back while holding her hands up. She chuckled as she saw the horrific look in the boy's eyes.

"Don't worry; I'm not going to hurt you. I'm not one of those human eaters after all. Instead…"

She glanced around to see if someone was paying attention to them. When the coast was clear, she grabbed a transparent bottle with strawberry-pink liquid out of her sleeve. She took a step closer to the boy, while pushing the bottle in his hands.

"Drink this before someone else notices you're human. You may 'disguise' as a demon, but you still smell like a human. Once you drink this, your human scent will disappear."

Marco suspiciously examined the bottle, even smelling if it doesn't smell like poison. Instead of some poison or disgusting smell, it smells sweet like strawberries. He gazed from the bottle to the girl.

"Why are you helping me?"

The girl chuckled once more and turned around, holding her hands on her back. Her eyes were directed to the ceiling for a while. She then turned around to face the boy again and smiled brightly at him.

"Let's just say I want to see a special dance before it becomes a slaughter party. Anyways, you don't have to drink that bottle if you don't want to. Well, good luck for now and in the future, boy."

She patted him on the shoulder when she passed him by. Marco didn't quite understand why she was wishing him good luck, so he wanted to ask her what she meant by it. However, by the time he turned around, a crowd was gathering as a demon, which looked like the ball organizer, asked for attention as he tapped the microphone.

"Hey, is it just me, or do I smell a human here?"

A demon asked who stood quite close to Marco, which startled Marco so badly that he breaks into a cold sweat. The demon next to him laughed and slapped on the back of the other demon's back.

"A human? Here? Ha! You must be crazy! There's no way a human could come to the Underworld. Doesn't princess Star reek of humans? She's living on Earth now, right? So maybe it's coming from her."

Marco was half paying attention to what the ball organizer is talking about, while listening more to the demons close by. He glanced at the bottle before glancing quickly at the demons.

"Maybe I should drink this just in case… if something bad will happen to me, I'm sure Star will help me."

He mumbled softly to himself while finding some courage to drink this mysterious drink. It didn't seem dangerous, but one doesn't judge a book by its cover either. That girl who looked more like a human than demon seemed kind. He sighed slightly and gulped the liquid in one shot, hoping no one else would notice that there's a human in the midst of them.

"...Hm, I feel nothing."

Once he drank the bottle empty, he looked at himself. At least he doesn't feel any pain or weird. His body didn't change into anything as well. He even sniffed at himself, but he doesn't notice anything. In fact, he still smells like nachos. Maybe that drink didn't work on humans? He shrugged as he was at least relieved nothing bad happened. Since nothing changed, he will just continue searching for Star once the speech or something was done.

"...binding them together for eternity in its hypnotic, ruby brodum."

The demon ball organizer finished his talk. The light of the blood moon covered the skylight opening as the eerie organ music started to play. While the music started to play, the demons started to dance.

"Ugh! That's the wrong piece of music! This is gonna drive me crazy. Alright, don't go anywhere. I'll be right back."

Tom shouted loudly enough for Marco to hear. Thanks to him, he found Star right away. Besides, Tom was even walking away from Star, which gives him a great opportunity to take her away from this ball! At least that was the plan before Star started to aimlessly wander around. He even called her a couple of times, but she didn't seem to hear him. Just when he was almost able to grab her arm, someone else grabbed his hand and pulled him towards them.

"Hey, do you have some business with my date?"

Tom did not want some demon stalker to follow his date. He won't let anyone ruin this dance with his date. When he saw some demon going after her, who was also inches away from grabbing her, he couldn't stand still. He grabbed his hand and pulled the guy with the skull mask towards him, so he would face the mighty demon prince. He asked the skull demon with a fierce tone what his business was with Star, trying to suppress his anger. Just at that moment, the light of the blood moon shines on them, drowning the ballroom in red light.