Because his mother fused her body with a livingstone air car while pregnant with him, he has the ability to grow wings. He's a shape shifter to only that degree. it work about like Rex's builds in Genrator Rex, although this was written many years before I saw Genrator Rex.
Because this happened to him before he was born, he has living stone in his genetic coding. His mother Emily could also grow and retract wings, but it does not pass down to her other children. Only people directly descending from him have this genetic code. only if a person with this code is a Chosen One they can pop out wings.
Therefore, Emily Scott-Harris can pop out wings. This is of no great significance, so far, except that SHE, not her mother, is the butterfly girl from her fathers dream early in life, the dream that brought him to D'zeron and destined him to marry her mother. Just a weird unintended twist.
Emily Hawthorn had white feathered "angel wings" and Isaiah had batlike wings, so apparently, the type of wings differs from person to person. [Rex has a jet pack thing, right?" .... living stone is something like Nanites, I guess? this is the first time I have made a connection between destny of dreams and Rex. dangerous moment...oct 30 2012]
Isaiah had one child with Josarenae Paragan, and one with someone else. I think Rae is his descendant so she also should have this capacity, but it is unlilkely to ever manifest in the story. She might have warned Serai though. She doesn't tell Jason every thing. He'll be surprised and dismayed