Dust, the weapon used by humanity to fight against the forces of darkness, monsters without souls. The Grimm. Combined with the aura of the soul as well as a weapon powered by dust one can become a powerful protector of mankind.

But what if someone did not use dust?

What if someone did not have a soul to project an aura?

Or even a weapon?

This, is the story of someone like that. Someone who uses rust, instead of dust.

The main hall of Beacon Academy lay in silence and in darkness, moonlight streaming through tall windows.

The eerie atmosphere was only broken by the sound of footsteps of Professor Ozpin, Beacon Academy's headmaster, taking a midnight stroll. His cane clicked against the marble floors he so vigorously cherished, but were such a pain to keep clean.

The headmaster stopped suddenly, in the middle of taking a sip of his coffee, his keen and trained senses picking up something that was not supposed to be here.

There was a burst of shadow, and a humanoid female form of a Grimm appeared. It held a small bundle in its arms.

Instead of attacking, though, Ozpin relaxed and smiled in familiarity. "It's been a while."

The creature chuckled with a raspy voice, "Likewise. The child has been completed, and his growth is exponential. When he was born his body was already a year old."

"Come, let me see him." The headmaster held out his hands eagerly to see the creation he had poured many resources into.

The she-Grimm went over to him and handed over the child, squirming in dark cloth. Ozpin looked at it with a twinkle in his eye.

"As expected, he will have the ability to fight like us. But there have been some... drawbacks." The creature shifted uneasily.

"And what would those be?"

"Well, unfortunately, he was born without a soul. So he cannot use his aura."

Ozpin waved it off, "He just needs to use a weapon, what type of dust could work with the b-"

"He cannot use dust."

The headmaster stopped, a new look of disappointment in his eyes. "So we failed."

"No, professor. We have actually created something... more powerful."

"Oh?"

The she-Grimm cleared her throat, "He may not be able to use dust, and thus not a weapon, or even his aura, but he can still fight like us. His body is strong. I tested his immune system with a small virus, and while his body suffered he acted as if nothing was wrong. The child has an amazing willpower, being able to block out pain."

"Hm. I see."

"But there is something he can use."

"And that is?"

"The material that comes off corroding metals. I do not know why, but it matches him perfectly."

Ozpin nodded, looking to the small bundle in his arms with a new future in mind. "Looks like we can still have some use from you, little beast."

The child shifted in its sleep, unaware of its intended purpose in life.