The lack of an answer from the treacherously unscrupulous merchant served only to cause another surge of white-hot anger to surge through Seidaku. Had that rage not been so fierce, he might have noticed how out of place it was, how out of proportion to the stimuli that had caused it.
Instead however, he felt a dangerous, deadly calm descend over his mind. Clearing his thoughts and imprinting a field of blank darkness across his consciousness as he felt the swell of Djed, twisting that darkness and calling across the veil between realities toward a darkness that mirrored and dwarfed it. Reality began to swirl between his clenched fist, a single point of blackness, ready to expand larger and devour the world.
The blankness of his thoughts, and subsequently the darkness between his hands, was dispelled in a spray of hot arterial blood across his face. Licking his lips in confusion, he tasted a metallic saltiness. He could do nothing but blink in disbelieving shock as the murderer turned and bolted away, shouldering him to the ground as he passed.
Shaking and hyperventilating at the sudden violence of the scene, and his own apparent willingness to participate, he could do nothing more than stare wide eyed at the spreading pool of blood beneath the merchant.
The other man, the one who had tried to talk him out of the sale was crouched over the man, trying to encourage him to stay alive. Dimly, Seidaku realized that he should be doing something. Trying to help stop the bleeding, calling for the guard, fleeing into the crowd himself. But no matter what he knew he should be doing, his legs would not obey his mental commands, and he remained sitting on the floor of the Bizarre, unable to comprehend what was happening around him.
OOCNo worries. I think it set the stage for Seidaku's own responses very well.