Aftermath
Amber did it first. Bright green fur sprang out all over her body, her claws elongated and thickened and she seemed to grow taller. Stefan followed suit almost instantaneously. Their faces lost their humanity when their mouths and noses elongated and combined into snouts and their eyes lost their sclera as their pupils seemed to widen and takeover the entire eye.
They growled at each other, howled fiercely, and ran, full force to attack. They were both all claws and teeth with Amber even taking a chunk from his leg with the claws on her foot.
This went on far too long with them still being evenly matched. In the end it was this aspect that ended everything. Over exerting your wolf will cause the entire body to shutdown and that's what happened.
They didn't truly notice at first. They simply slowed down a bit which could've been attributed to fatigue. In the end they were both on the ground in a deep hibernation type sleep.
