In a few words, the best way to describe Nyria's physical changes would be to say she's matured. In doing so, the colors of her multi-toned blue feathers had grown brighter, and even though they felt soft to Aoni's touch, visually, they appeared sharp and dangerous.
If he didn't know any better and hadn't been petting the fledgling, Aoni could have sworn she was covered in razor armoring or plated scales instead of feathers.
The patterns around her face gave a feeling of danger and fierceness that was betrayed by her kind eyes. Her beak, which was once shaped like a giant sunflower seed, now resembled an arrowhead, which no doubt would allow her to stab foes or prey. When paired with the extremely sharp yet small hook shape at its tip, Nyria could probably do more damage to something or someone than Aoni could with his hook blades.