Juane Arc. In another life he would not have his aura unlocked. He would fake transcripts, join Beacon, and nearly die in initiation before having his aura unlocked by the Mistralian Champion Phyrra Nikos, and go on to become the leader of team Juniper(JNPR) with an overwhelmingly large aura and a semblance able to overcharge aura, whether his own or others, and continue on to save the world of Remnant.
This… is not that story.
Juane Arc joins Beacon with fake transcripts, desperate to become a hero, but his motivation is not to overcome his own perceived failure, but to overcome something else. For this Juane does have his aura unlocked. And even his Semblance discovered. But you can bet he's going to hide it because it's not a very heroic ability, and his aura is practically non existent, barely making him any better than a civilian without any aura at all.
Pyhrra still attempts to unlock his Aura, thinking he doesn't have any, but in turn only supercharges his own, something that doesn't last very long at all, but does at least get him through initiation at least.
But it all comes out the first time Juane takes a hit in combat class and is nearly killed. After he recovers, he's brought before Ozpin and he confesses his low aura to the man, but most importantly his semblance. The Semblance he calls…
Aura Breaker.
Juane, rather than supercharge others aura, instead saps it, dropping his aura to barely nothing, making it hard for Grimm to detect him, but not impossible, but more damningly, all of his attacks go through aura like it's not even there, making all hunters seem all too… human.
Now it's up to Ozpin to keep this devastating weapon secret from Salem and help Juane's dream to be a huntsman come true, to prove to himself he can be a hero… despite a semblance perfectly made to break humanity.
But what else is Ozpin planning? After all, he's not the only one with human allies, and while immortal, Salem was once human too…
But surely it's not safe for Juane to train in a school for superheroes when his own ability makes them all seem like they're made of glass… Can Juane keep the secret? How will others react if they find out? Will his team still accept him if they know that as powerful and safe as they are with aura, around him, they're not?