The theory checked out.
Next came the practical test.
Keyaru was already very fluent with using Heal. As the gentle glow gathered in his palm, he swallowed his nausea and pressed his hand to the goblin.
The images of its limbs being hacked off during the fight replayed before his eyes—and he immediately cut the healing short.
He looked at the goblin's wounds, now closed and no longer bleeding. His brows knit. The result was sitting there in plain sight—and it wasn't what he'd planned.
"Where exactly did it go wrong?"
Magic.
Fully grasping the concept felt a bit out of reach for a modern mind like his. Right now it was like: you fill in an entry quiz for an entrance exam and score a perfect zero, your family buys you a tech-college diploma, and the acceptance letter that shows up says "Hogwarts"—but Platform 9¾ is nowhere to be found.
"If I'm remembering right… in DanMachi there aren't elemental 'attributes' on mana."
His frown didn't ease. He dug for details he'd glossed over in the anime. The clearest example: Loki Familia's vice-captain, Riveria Ljos Alf, the strongest mage in Orario, nicknamed Nine Hells—not because she had nine different spells, but because she could wring nine distinct effects out of her three spell slots.
Mana itself felt more like generalized mental power; the post-cast dizziness ("out of mana") was just overdrawn psyche.
"So… can I change mana's output form by changing my intent—my mental expression?"
Even setting aside Hestia's relationship with Loki, he had no way to get near Riveria as a nobody. He'd have to free-think it.
Time was on his side. He looked at the goblin carcass and decided to try a 'change the shape through intent' approach: could he morph Heal into a Corruption-type effect?
"Grimoires give you magic, but the user's ideas and experiences shape what that magic becomes. The rabbit's flame-and-lightning—pretty sure that's how it worked."
"Maybe this will actually do something."
He braced for failure. DIY skillcraft, after all. He focused, changed the image, tried to twist the form—and before he even touched the goblin, the half-healed monster writhed, trying to bite him.
He ignored it.
"Corruption?"
He triggered Heal—but no gentle glow bloomed. Instead, his mental power was yanked dry. His vision went black for a beat; he nearly collapsed.
When he steadied himself and looked at the goblin—its whole vitality crushed, body severely weakened—the only thing in his eyes was the thrill of success.
"Did I… pull it off?"
Heal had only ever closed wounds—reconnected limbs. But that last cast had wrecked the target's insides: organs failing, life ebbing—Corruption.
You test a new skill with proper controls. Keyaru ended the goblin with a short sword, bagged the drops, and did not push deeper. Heal alone was tiring enough; adding a second, reshaped Corruption cast had drained him hard. Rushing off to "clear content" on hype was how most rookies got themselves killed.
He would keep his respect for the Dungeon.
"I'll run a few more trials. If the results match, I can call it a developed derivative: Corruption."
At the end of a quiet corridor he rested until the out-of-mana dizziness faded and he felt solid against the Dungeon's surprises—then moved again. Target: weak monsters. Same setup as before.
Corruption.
The familiar vertigo washed over him—this time he saw it: the goblin's severed torso shriveling at a speed visible to the naked eye, muscles deflating like a punctured ball.
"That's the feel!"
His grin couldn't hide the fatigue in his eyes. Corruption was blatantly overtuned—but the cost was, too: mana and stamina bled fast. He couldn't spam it like the Hero of Healing after stacking stats with Looting.
If only he had the Georgius divine armor—then Corruption would be his ultimate trump in DanMachi, with that handy "HP-lock" survival passive on top. Next milestone: extend Corruption to a 1-meter aura, not just touch-range.
Even so, he was elated—not just because he'd learned Corruption, but because he'd found a method to develop skills.
Transformation. Looting. The Redo of Hero roadmap gave direction—but if he just followed it without the same pressure-cooker environment, he'd end up with a discount copy.
"I need to walk the Healer's path my own way."
Goal set, he pushed deeper and kept the momentum, turning back to Transformation for a real, substantive power-up. His stats were already beyond shallow-floor standards, and his live-combat technique did the rest. Clearing out blockers felt almost easy.
Soon he reached yesterday's limit—Floor 5.
It was too quiet. Visibility was low; no monsters in sight. He stayed wary—until several black stains pooled on the floor ahead…
…and congealed into human shapes: War Shadows, the rookie-killers.
"Three?"
"No—Shit, they're still forming!"
He'd fought War Shadows—but not this many at once. He didn't flinch. Using the same induction as Corruption, he reshaped Heal into a short-duration stat buff:
Transformation.
"Good."
"Let's see where my limits are with Transformation cranked."