NKret

Don’t stop. Keep moving—harder, faster.

One tear sealed, now another.

Celine couldn’t remember the last time so many demons had broken through Honmoon. Countless hordes pressed in, a tide of bodies and claws. She knew she wouldn’t be able to save everyone. She closed one tear only for two more to appear in its place. The barrier always weakened in autumn, but never this much.

A lie.

She remembered a much larger horde all too well. Something precious had been taken from her then.

No. Don’t think about that. Not now.

Slash. Stab. Dodge.

A breath.

Another tear.

Repeat.

Exhaustion soaked into muscle and bone. Her body faltered, but she couldn’t stop. No matter how much she bled, how badly she limped, Celine cut down demon after demon.

Slash. Stab. Dodge.

Day gave way to night, but that meant nothing to the demons. The glowing installations around Cheonggyecheon meant nothing either.

Three hours ago Celine had gotten a call from Jeju—the demons had attacked the island. Mentors and a few mudang had gone to defend it.

She was alone. Just her, Seoul, and endless demon hordes.

The sun chased away the moon, thick clouds gathering overhead.

The boy—Celine refused to think about how, in another world, Rumi would be his age—dissolved before her eyes. Another soul she couldn’t save. Another she had failed.

The world wept and Celine wasn’t sure whether the drops on her face were rain or her own tears.

Slash. Stab. Dodge.

Night again. When had the sun set?

Celine leaned against a wall. Her body begged for a break, but she knew that if she sat down now, she’d never find the strength to rise again.

There. Another demon.

She clenched her teeth and, even as her body screamed for her to stop, she pushed forward.

The world swayed and blurred. Honmoon still wailed, but much quieter now. An hour had passed since the last tear.

Walls and bulletin boards were plastered with a terrifying number of posters. So many families would never see their loved ones again. All because of Celine. If only she had tried harder.

The world tilted.

No. No no no. Not now. Not now!

A pair of arms wrapped around her waist.

She closed her eyes just for a moment. And again those hands—soft and deceptively strong. They helped her into the elevator, then into the apartment, then into the bathroom.

Celine didn’t react to the sting of her wounds or the needle running through her skin. She deserved this and far more.

A soft blanket settled around her shoulders. No, she should be sitting here alone, in the cold bathroom, bleeding and paying for every failure.

When had she ended up in the bedroom?

Mi‑yeong and Hana looked at her from an old photograph. What would they think of her? She was supposed to be a fearless leader. Unbreakable. But she had failed. Failed so terribly.

She slid to the floor. The blanket slipped from her shoulders, her face buried in her hands.

With a volume of 3.6 L, this gives an average density of:

3500 g ÷ 3600 cm³ = 0.97(2) g/cm³, approximately 1.0 g/cm³.

The prosthetics were made primarily of titanium (50% of whole mass), with 1 cm³ weighing about 4.5 g.

Assuming an average density of 2.8 g/cm³ and a volume of 3600 cm³:

3600 × 2.8 = 10.08 kg, meaning the left‑arm prosthesis weighs about 10 kg.

The right prosthesis replaced only the hand and forearm (about 40–50% of the limb’s total volume):

0.45 × 10 kg = 4.5 kg

A 10 kg left arm and a 4.5 kg right arm is a brutal imbalance. This is where the exoskeleton comes in.

The implant along her back spanned ¾ of the spine.

Volume: 0.9 L = 900 cm³

Density: 2.8 g/cm³

900 × 2.8 = 2.52 kg

For both legs (which make up about 20% of total body mass per leg), let’s assume the implants weigh around 10 kg.

The implants within the chest area add another 3 kg.

Total equipment mass:

10 + 4.5 + 2.52 + 10 + 3 = 30.02

Rounded: the equipment weighs about 30 kg.

Rumi’s mass before and after modifications:

Biological mass (fully human): 65 kg

Mass after amputations (left arm 3.5 kg and right arm 1.75 kg): 59.75 kg

Mass after adding the equipment: 89.75 kg