Castillian #1: Sinner's Formula

Throughout the engineering department, Clarisse Santiago was well-known.

Top of the class. Captain of the Robotics Team. Always presentable, always looking fresh even when sleep-deprived. And most of all—she had long been openly obsessed with Mico Cein Esguerra.

In her eyes, they were perfect for each other.

Both smart. Both achievers. Both ambitious. Both suited for LinkedIn, not Wattpad.

So when rumors started spreading about Mico and some "low-level, cute girl who didn't even know how to solve for x," she wasn't pleased.

Scarlet? That clumsy, average, zero-accolades girl from IT? Seriously?

No way.

She wasn't having it.

It started subtly.

Clarisse would pass by Mico in the hallway and "accidentally" brush her fingers against his arm.

"Oh, sorry. Didn't see you there," she'd say with a soft smile.

Mico barely even nodded.

She'd try sitting beside him in the engineering lounge. Offer him coffee. Compliment his notes. Wear perfume she googled to be "scientifically proven to attract men."

Nothing. No effect.

And still, she kept trying.

This time—bolder. More desperate.

One Rainy Thursday | Engineering Lounge | 5:45 PM

"Hi," Clarisse said sweetly, approaching Mico who was quietly working alone. "Everyone's tutoring these days. You're inspired now too, huh?"

Mico didn't even look up. "Do you need something?"

"Don't you even want to ask why I'm here?" she teased, sitting across from him—uninvited.

"No."

Clarisse giggled like that was the cutest thing she'd ever heard.

"You're cute when you're cold, Mico."

Mico looked up. His face was blank. Dead eyes. Stone cold. Like a robot that just received a corrupt command.

Clarisse leaned in, letting her fingers trail across the table, inching toward his hand. "I mean, I've always thought we'd make a great pair. You know. You and me. Same wavelength. Same goals. Same—"

"I don't like arrogant girls who think they're entitled to someone just because they have credentials."

Clarisse froze.

Mico leaned back, his voice now made of steel. "And I especially don't like anyone insulting someone I care about."

"You mean… her?" she scoffed. "She's beneath you, Mico. You know that. She's not as good as you. She's done nothing worth—"

"She's mine," Mico cut in, eyes darkening. "And that's all that matters."

Clarisse's smile faltered. "You can't be serious."

"I don't owe you anything, Clarisse," he said, already packing up his stuff. "Try touching me again, I swear I'll ask Coach to make sure you're banned from the next campus scrim. You're becoming a nuisance."

Then he walked out, leaving her humiliated, sipping on what was left of her pride… as the rain poured down.

Meanwhile…

Scarlet was lying on her bed, wearing oversized pajamas, hair up in a messy bun, munching on chips while reading modules on her laptop.

Her phone lit up.

Mico:

Have you eaten, baby?

You're probably hungry again but too shy to say.

Or maybe… you wanna eat me?

Scarlet choked on her chips.

"H-holy—"

Another message came in.

Mico:

Just kidding.

(but also… not kidding, if you're into it)

joking. (unless?)

Scarlet buried her face in her pillow, squealing. "Mico, what is wrong with you?! My god."

Then another ping.

Mico:

📸 Photo attachment

A mirror selfie of Mico in gray sweatpants and messy hair. Holding a review book. No shirt.

Studying. Miss my professor.

Scarlet: DEAD. ON. THE. SPOT.

She replied:

Scarlet:

Are you really a professor or just a pervert disguised as an honor student??

Mico:

It's just me. Your pervert boyfriend.

Reminder: it's you and only you, Scarlet.

Scarlet melted. Like microwaved cheese kind of melted.

"My god, you're the number one enemy of my focus."

What Scarlet didn't know?

While she was giggling into her blanket,

someone else was crying inside the bathroom of the engineering building.

- 🏀 -

Clarisse Santiago was not done.

Not when everyone kept whispering. Not when the posts about Scarlet Fuentabella kept multiplying.

And especially not when Mico—her Mico—still looked at that girl like she was the goddamn sun.

No.

Clarisse wasn't stupid. She saw through the charade. Scarlet was just a phase. A nobody. An accidental interest.

So she made a decision. If Mico wouldn't come to his senses, then she'd bring out the truth. Or better—expose Scarlet and destroy her image.

Saturday | 9:11 PM

Scarlet wasn't answering messages.

She hadn't posted anything either.

Clarisse, tucked in a hoodie and low cap, stood across the Engineering building, quietly lurking like a ghost.

Then she saw it. A shadow. Then two.

She squinted. The abandoned annex building? Why is someone going in there?

Her eyes widened. Scarlet. And Mico.

Mico Cein Esguerra, the untouchable king of Castillian, sneaking into an old, condemned faculty building—with a girl in tow.

What the hell are they doing there?

Quietly, Clarisse followed. Her footsteps like secrets.

She stopped by the shattered window. She saw them.

And what she saw made her breath hitch.

Mico had Scarlet gently pinned to the wall.

She was flushed, teary-eyed—but her lips were swollen. Mico's shirt was half-unbuttoned. His hands were under her skirt.

And Scarlet—her panties were around her knees.

Clarisse gasped.

Mico kissed Scarlet again. Deep. Filthy. Possessive. With the kind of hunger that shattered Clarisse's delusion into pieces.

Scarlet whimpered. "M-Mico…"

He pulled back slightly. "Still okay?"

She nodded, tears clinging to her lashes—not from pain, but from being overwhelmed.

"Only you," Mico whispered, kissing her jaw, then her throat, then her lips again with a tongue that was anything but gentle. "Only you, always."

Clarisse couldn't move. She was frozen.

This wasn't a girl being seduced. This wasn't a fling.

This was… love. Dirty, intense, chaotic—but real.

Then she remembered her phone. Her hand fumbled inside her hoodie, pulling out her camera with trembling fingers.

If she captured this, she could end Scarlet.

She raised her phone.

But before she could press record—

"Put that down."

Clarisse jumped, twisting around.

A figure stepped out of the shadows behind her.

Jairo.

Jairo Roman. "The Beast" of Castillian.

His arms were crossed. His stare? Like ice.

"M-Mico sent you?" She stammered.

"I've been watching you since Thursday."

Clarisse backed away. "I was just—"

"Planning to destroy the only girl he's ever cared about?"

Silence.

"Go home, Clarisse." Jairo's voice was calm, but deadly. "You don't belong in this story. And next time you try to record something that's not yours…" He stepped forward. "I'll make sure you won't be able to scroll again."

Clarisse dropped her phone and ran.

Inside the annex

Scarlet was still shaking, though Mico held her close, fixing her skirt and gently wiping her tears.

"Sorry," he whispered. "I got carried away."

She smiled tiredly. "It's okay. It's not your fault. I was the one who said… I wanted it."

He kissed her forehead. "I won't ever do this in a place like this again. I want you safe. Always."

Then he kissed her lips again—slow, reverent.

And for the first time, Scarlet whispered back—

"Only you too."

Meanwhile, Jairo was already texting.

[Jairo]:

She saw. I stopped her. You were right.

[Mico]:

Good. Keep it that way.

No one touches her but me.