F Grade Healer Becomes Strongest Biomancer-Chapter 52: The Marrow

Mio

Ivory led them deeper into the titan.

The ribcage alone was the size of a stadium. Mio’s footsteps echoed wrong — too hollow, eaten before they reached anywhere.

"First things first!" Ivory spun on her heel, nearly tripping. "Inventory assessment. What are you carrying?"

Mio pulled up the screen.

[Inventory]

Aoi’s Hair Clip x1

Putrid Core x1

+489 others...

"Mostly junk," Mio said.

[Appraisal]

Ivory’s eyes glowed violet. She scanned the list without touching anything.

"Trash, trash, trash, decent, trash, ooh that’s nice, trash, trash—"

Her eyes widened.

"Mio-san. Is that a Putrid Core?"

"Oh, this thing?" Mio pulled it from her inventory. It materialized in her right palm — the size of a golf ball, purple and crystalline, like a lollipop without its stick.

Mio’s mouth started watering. She caught herself.

Nana came up behind Mio, her mouth watering next.

"Can I eat it?"

"No," both girls said at once.

A prompt appeared in the corner of her vision.

[Consume Putrid Core?]

Cost: 200 VIT, 75 STR Effect: ???

[Requirements not met]

Mio put it back in her inventory, then dismissed the screen.

"As expected." Ivory smoothed her coat. "There are requirements still to such power-ups. Heh."

"How much for everything else?"

"Liquidating everything except the clip and the core..." Ivory squinted. "About 8,200 lumens. Give or take."

Four hundred items for eight thousand. Mio tried not to feel insulted.

"Do it."

[Liquidating items...]

[+8,247 Lumens]

The junk vanished from her inventory. What materialized in her palm wasn’t coins.

Bars. Gold if it was marble, glowing faintly from within. She recognized them — lumens, the system currency. What converted at the Bureau kiosks for yen. Usually she got coins from incursion drops.

She had bars.

She’d be rich if she sold these at the Bureau.

"So!" Ivory clapped her hands. "What would you like to purchase?"

Mio stared at her. "I don’t know. What do you have?"

"Everything! Ability upgrades, equipment synthesis, stat augmentation, incursion seeds—"

"I don’t know what I need."

Ivory’s smile faltered. "Oh."

In the background, Nana had started climbing a vertebrae column.

"Well." Ivory glanced at Nana. Back at Mio. Back at Nana, who was now halfway up. "Perhaps we should— Nana-chan, please don’t touch that— perhaps we should establish a baseline first."

"A baseline."

"Yes! To determine what suits you best." Ivory pointed at a titan rib, still watching Nana from the corner of her eye. "Punch that."

"Why?"

"So I know what you’re working with. It’s reinforced marrow bone. Very dense. Very— Nana-chan, that section is unstable!"

"I’m fine!" Nana called down.

Mio shrugged. Walked over. Pulled back her fist.

Her arm went through the rib.

Ivory blinked.

"Um," Mio said.

"That’s not supposed to happen."

"I’m stuck."

"That’s really not supposed to happen."

Nana’s laughter echoed from somewhere above them.

It took five minutes for Ivory to pry her loose. Something about "bone memory" and "recalibrating density expectations." Mio didn’t follow most of it.

When her arm finally came free, Ivory was scribbling furiously.

"Very good! Comparing your current output to your initial level one state..." She flipped a page. "If you had fought the Putrid Knight—"

"Can," Nana interjected. She’d made it back down at some point.

"Can! If you had fought Can in its decayed state, that punch would have dented its helm in!"

She tested the joints in her obsidian arm. Couldn’t hide her smile.

"Ivory-san, why don’t you try giving it a go?"

"No need!"

"Please?"

"There is absolutely zero reason to do so!"

"I’ll tell Gaian you failed to get me to buy anything."

She gasped.

Then pocketed her notes.

Ivory walked to an unmarked section of rib. Rolled up her sleeve. Drew back her fist.

She punched.

Her knuckles met hard marrow.

"Ow." She shook her fingers. "See? That’s that. Now purchase some seeds, and choose from what I’ve decided works best for you!"

Mio looked at the crack she’d left. Then at Ivory’s unmarked target.

Nana squinted past them. "Um. Ivory-san?"

"Yes?"

"What happened to the bones behind it?"

Mio turned. The vertebrae column twenty meters past the rib — the one Nana had been climbing — had shattered to dust.

"Oh." Ivory dusted off her knuckles. "Hollow techniques."

She didn’t elaborate further.

Ivory sat on a flat section of bone, patting the open space for the Tamei girls.

"I’ve narrowed it down to what suits you best! Please wait while I connect the Marrow to your System."

[Ability Upgrade: Vitalize+]

Cost: 75,000

Reservoir Effect: Vitalize can now target allies within 5m. Healing output unchanged.

"Option one! Your healing can target others. Very useful for squad work."

Mio thought about Kaito. His chest wrapped in bandages. Seven years left.

[Ability Upgrade: Spark+]

Cost: 75,000

Reservoir Effect: Spark can bond to metallic surfaces. Lightning affinity +30%. Synergizes with Ironblood trait.

"Option two! Your lightning bonds to metal. Very zappy with that arm of yours."

The obsidian arm caught what little light existed in the void.

[Passive Attunement: Final Vigil]

Cost: 75,000

Reservoir Effect: Final Vigil cost reduced to 25,000. Output condensed. Strain reduced 200%. Overall damage reduced 40%.

"Option three! Your big attack becomes usable. No more debt spirals."

Mio remembered the -98,000 hole. The agonizing days it took to climb out.

"And the seeds?"

[Incursion Seed: Nested]

Cost: 4,500 Reservoir

Effect: Generates a nested incursion. Scales with user level. Repeatable.

"Maximum efficiency and dynamic growth!" Ivory beamed. "Optimal for your current state."

Nana tugged her sleeve. "What’s dynamic growth mean?"

"The incursion scales with you. The stronger you get, the harder it gets."

Mio looked at her Reservoir.

[Reservoir: 82,058 / 287,500]

Then at her options.

"Can I come back and choose later?"

"Nope!" Ivory wagged her finger. "Gaian’s— Er, I mean O’ Great Devourer’s dimension attunes to your state of mind and needs per instance of entering the Marrow. You get what you get."

"So if I leave without buying..."

"Gone! Poof! Maybe something similar shows up next time, maybe not. The Marrow is fickle."

Mio stared at the options.

Vitalize+. She could heal others. Kaito with his bandaged chest. Nana if something ever—

No. Don’t think about that.

Spark+. Her arm was metal now. Lightning and obsidian. Can’s old instincts were already there, waiting.

Final Vigil attunement. One use had put her 98,000 in debt. Agonizing days of climbing out. But condensed output, reduced strain — she could actually use it without gambling her life.

And the seeds. Eighteen of them would let her grind forever. The war Gaian showed her wasn’t coming tomorrow. She had time.

Do I have time?

"Onee-san." Nana tugged her sleeve. "You’re doing the face."

"What face?"

"The overthinking face."

Mio looked at her sister. Then at Ivory, who was practically vibrating with anticipation.

"How long do I have to decide?"

"However long you want! But the door might open any second and then you’re out of time anyway."

Great.

"Onee-san." Nana wasn’t tugging her sleeve this time. She was pointing.

Mio turned.

Light. Faint at first, creeping across the void. A sunrise in a place that had no horizon.

And beneath it—

Flowers. Hundreds of them, scattered across the bone fields. White and simple, their petals catching the new light.

Moonpetals.

Ivory had gone quiet. For once, she wasn’t fidgeting.

"The One Who Devours plants them for every champion," she said softly. "When they die."

"How long has this war been going on?"

"A thousand years."

"Oh."

The door behind them hummed. Ready to open.

"I want the Final Vigil."

[Purchase confirmed]

[Reservoir: 82,058 → 7,058]

For eight hundred years, Can held a threshold, bound to his vigil, and when it ended he still chose to stand his ground.

Mio would too.