As soon as Rogue was through the window and distracting Sabertooth, Sinister flowed through the opening left by the remaining shards of broken glass. Like water through the cracks of pavement until he was reformed in full and walking over the mundane apartment floor. Blood and further breaking glass squelched under his feet with muted pops and crunched as he made his way to the side of the bed and did a cursory examination of the boy.
Well, he was still alive. Creed wouldn't have to die. He would certainly need to be reminded that Sinister was someone to be afraid of, but he wouldn't need to die.
With gentle, deft hands, the doctor began releasing his son from his bonds, speaking in a low, comforting voice as he did so, "Remy, you can stop screaming for me now."