"I think I'm just supposed to disrupt the magic flow like this and-"

He was, in fact, not supposed to just disrupt the magic flow like this.

Raw, uncontrolled power immediately rose, bursting through everything in it way and tearing to shreds all the metamorphosis magic that remained. Ken's physical appearance melted away, and power concentrated, and expanded, and solidified again, until where a young boy was before now stood a gigantic dragon.

Ken was in pain and couldn't even process what was going on. Onlookers, however, could see his new reptilian form. They could see his enormous size, likely 300 feet from his snout to his tail tip. They could see his black scales, they could see his glowing red eyes, they could see the huge spikes protruding from his spine, they could see the mass at the end of his tail. They could see the massive wings that cast a shadow on the nearby buildings, they could see the long, razor sharp claws, they could see the golden veins that seemed to course through his body, they could see the aura of blue flames engulfing him.

And they could see him thrashing around, him roaring, him clearly suffering.