"And how hard is it for fairies? I'm told you're immortal; we might weigh time investments differently." As he speaks, Armsmaster dismantles the piece of his halberd they tested and tinkers with the inside.
"I've lost track, but I think I'm less than a hundred years old. I started learning sorcery when I was very new. I'm pretty talented at it, but I could do simple things within a few years of work."
"What would be a reasonable amount of progress in the first few weeks? Assume ideal harmonics." He reconfigures the machinery, doesn't bother closing the casing, and turns it on. "Map the area again, please."
"With flat harmonics you could probably learn to do lights in the first few weeks, and maybe one other thing, like purifying water or warming things up." She re-maps the area.
"Or cooling things down?" He checks the sensors to tell what non-harmonics things were affected by the altered device, then rearranges it again and holds it out.
"How long before I'd be able to make a gate?"
"Gates are complicated. I'd been a sorcerer for years before I picked up the skill and it took me weeks."
"I learned healing pretty early but it's complicated and you really have to know what you're doing or nasty things can happen, which would probably be worse for a mortal than for a fairy, you could actually die doing it wrong... making yourself stronger I don't actually know how to do, but it seems doable, I could probably figure it out, but it's not common or basic."
"The cooling alone could let me fight Behemoth for that much longer, but if it's just that I'd be better off working on something else. What do combat sorcerers usually do in your world?"
"Depends on the end goal. Turn other fairies into animals, sometimes. Fire and lightning and ice. The opposite of healing is strictly speaking easier than healing, all else being equal. Occasionally rapid plant growth sees combat use."
After a few more iterations of seeing what changes the distribution of fairy lights, he feels like he has a decent grasp on what kinds of things affect harmonics. He moves on to testing the more promising ones for what kinds of changes they have.
She continues to map the square as they go, pausing once to get a new map of the unaltered region in case it has changed (it has).
Apparently unsatisfied with the pieces in his halberd, Armsmaster starts dismantling one of the less important observational equipment. He grabs a particular piece, reassembles the by now unrecognizable device, and tries it again.
"Truly flat harmonics would be amazing. If a potential liability once any other sorcerers noticed that was what was going on."
"Usually a fight between two sorcerers of similar skill is decided by who knows the territory better. A harmonics-flattener would destroy that advantage and replace it with an advantage from the person who knew the harmonics were flat, but only until that occurred to their opponent."
By now he has cannibalized part of his leg armor for a particular piece. Oh well, wasn't moving around much anyway.
"Or something similarly chaotic, yes. Then whoever has the machine would at least know which state the battlefield is in and when."
"Good sorcerers can adapt to conditions very rapidly, but yes, that might make a large difference."
After a particularly favorable result on the next test, Armsmaster asks "Can you try this one outside?"