Demigods: In Paris (a Miraculous Ladybug and Percy Jackson crossover)

3 Hawkmoths, chilling in a hot tub~

 A flash of purple light shone blindingly bright for a second, then faded to reveal Percy, looking almost exactly the same but with a silver and purple eye mask, and a pale purple streak alongside the grey one in his dark hair. Even his clothes had remained unchanged, but he didn't pause to look at himself. One of the many surrounding butterflies immediately fluttered into his bare hand, and he cupped the other over it automatically. Carapace watched in fascination as light gathered in his palms, and he released the butterfly. Unlike Hawkmoth's black and deep purple ones, Percy's akuma was silver with dusty lilac patterning, and it hastily flew past Hawkmoth, towards where the sounds of the girl's shouting were coming from.

"No!" Hawkmoth jerked to life, like he'd been lost in thought and hadn't noticed what was going on. He lunged towards the akuma, but Chat Noir extended his baton and tripped him over and it flapped out of his reach.

Queen Bee's timer beeped two minutes.

"If Percy has the miraculous, and he's not an illusion..." Carapace wondered out loud, staring at Hawkmoth. "What is he?"

"A sentimonster!" Ladybug gasped. Hawkmoth laughed. 

"This may be a sentimonster, but by using it I have all of my powers at my disposal! I can-"

A lilac butterfly shape appeared around Percy's eyes, and he gasped. "Uh, hi?" He asked, then seemed to listen to something. "Yeah, it's me. I used it. I'm pretty sure I get to give you a power, what do you want?" Another pause. "Okay. Telekinesis, coming right up." The butterfly faded, and Hawkmoth the sentimonster went slack. Carapace guessed that Gabriel was too busy trying to stop Annabeth from escaping to control him right now.

A second later, Annabeth burst out of the darkness, ripping tape off her mouth as she ran. "Thanks, seaweed brai- You dyed your hair without me?"

Usually akuma victims were changed as well, but Annabeth looked exactly the same as usual, save the matching lilac streak in her hair. Carapace didn't know if that was just what happened when the miraculous was uncorrupted, or if it had something to do with what Ladybug had said about the two of them being special.

In the corner, there was a series of rapid beeps followed by a yellow flash and a gasp as Chloé crumpled to the ground. She stood up hastily, brushing herself off.

"Took you guys long enough," she grumbled.

"This is so weird," Annabeth muttered, touching her head. The Hawkmoth sentimonster jerked back to life and Annabeth lifted her hand, immobilising him in mid-air. She grinned. "Awesome."

"I thought you were the superior one for not having powers," Percy teased.

Annabeth gave him a Look. "Seriously, Seaweed Brain? Who doesn't want powers? I just didn't want to seem jealous."

"Oh."

"Ladybug, what are we doing now?" Rena Rouge yelled. 

"Ladybug, you're so secretive with your identity. Would your friends follow you so willingly if they knew who you were?" Gabriel stepped into the light, and Annabeth switched her attention to him in her haste, dropping Hawkmoth. The sentimonster snatched up a butterfly and infused it with dark power, absorbing the akuma before anyone could stop it.

 "I give myself the power to see a person's true identity," it intoned, not even pretending to act like the real Hawkmoth anymore.

"Lucky Charm!" Ladybug shouted hastily, arms outstretched to catch the object.

"Quick!" Carapace dove out of sight as Sentimoth's transformation completed, and Ladybug didn't have time to catch the lucky charm before Rena Rouge pushed her behind the shelter with him. Chat Noir and Chloé, still waiting for her kwami to recharge, stayed in the open, but Carapace was surprised and more than a little confused to see Percy and Annabeth hide as well.

The lucky charm fluttered quietly to the ground. He couldn't see it clearly without revealing himself, but to Carapace it seemed to be some kind of fabric which lay pooled on the ground near a clump of some sort of whitish foam.

"What do we do?" Carapace hissed. Ladybug looked wildly between Gabriel and Sentimoth. 

"I can't get out there to try and use my charm, he'll see me..."

"Can't Annabeth and Percy distract him?" Alya hissed back as Sentimoth prowled closer. The two of them were having a heated discussion behind a screen on the other side of the room. Chat Noir was arguing with Gabriel whilst Chloé wasn't paying attention. Sentimoth was closer now - too close. It was about to look over their shelter and reveal them all when it suddenly dropped to the ground, then vanished. A white feather fluttered out of Gabriel's pocket, and coughing sounded from the darkness Annabeth had come from. 

"Nathalie!" Gabriel ran towards the coughing. Chat stepped in his way, and when Gabriel tried to push past he extended his baton to trip him up again. They all rushed out of their hiding spots, then hung around awkwardly. They couldn't exactly attack Gabriel when he wasn't trying to harm them, but he couldn't get away with his crimes.

Carapace couldn't see a way out of this cycle. Years of being Adrien's friend had taught him how stubborn his father could be, and he knew that Gabriel would never give up his quest, even without the butterfly miraculous. The entire situation felt hopeless, and from the faces of his fellow heroes he knew they felt a similar way. They may have won this fight, but the war would be endless.

Percy and Annabeth, however, had no qualms in restraining an unarmed man. They rushed forward and pinned him with ease. A roll of tape came floating out of the shadows, and Gabriel's eyes went wide.

"Wait-" But there was nothing he could do as the roll of tape unravelled itself and magically circled around him, binding him in a cocoon of plastic before he could get out another word. Only his nose and his hateful eyes were left uncovered.

Percy's miraculous beeped, and Ladybug's followed a moment after. She had four minutes left; he had two. Annabeth smiled sadly, clearly melancholy about the thought of losing the power she'd just gained. Nino bet that if he had been in control of himself when he was the Bubbler, he wouldn't have wanted it to end either. 

But Annabeth didn't say anything like that. "Better get this wrapped up," she said quietly, nodding towards the darkness.

"I think you wrapped it up quite thoroughly," Chat punned half-heartedly, gazing at his father wriggling on the floor like an overgrown caterpillar. As if reminding them of her presence, Nathalie coughed from the other room. 

Warily, they all trooped through the shadows towards the sound, weapons at the ready. Carapace's jaw dropped as he saw what lay beyond the gloom, and Chat Noir fell to his knees.