What happens when a semblance evolves from sheer stress and fear instead of natural growth? You get corruption. Ruby's semblance evolved to be more destructive as a defensive mechanism, and you showed up. Your the wolf, as her semblance developed sentients to share a head space with her.

Her new semblance has her petals produced by Petal Burst become razor sharp, often getting lodged in flesh if used around anyone. And you, the wolf, tend to react when something even remotely dangurus is around or when Ruby's emotions spike.

Consider this a honorary 90 followers special, and my (hopefully) formal return.

Rwby