The wolf smelled a flash of hesitation and seized upon it, but Faelan was still himself inside and, summoning all his strength, he battled, reminding himself that he didn't want to hurt Sirius. Sirius had said he needed Faelan to help if he could, so he grabbed onto that anger and tried with all his might to turn it on the wolf.
Sirius was resolute and the magic was strong. The spell didn't let up and after a minute of struggling, Faelan felt his chest begin to lighten and his bones tremble. He was gaining control! It had only been days, but he'd forgotten how much more free his insides felt when the wolf wasn't pressing in upon them. He wanted so badly to be free.
With one final snarl and a physical effort so great that he thought he might burst with it, he shoved ruthlessly at the wolf, and before he knew it, it was upon him.
The change came as it always did, with breath-taking agony, but when his joints dislocated and muscles ripped, they reformed as human, and when Faelan fell to the floor on his hands and knees, he collapsed, wanting to cry with the glorious relief of the pain.