Noah couldn't afford to let Mark continue to irritate him, lest he end up mindlessly killing him, as he did with the man in the shower. He had hoped that giving into his monster inhibitions, allowing himself to feast on the Zombie King, would make the decision to kill someone less conflicting. Yet, even now, the thought of ending Mark's life didn't bother him. To his surprise, he even felt himself salivating at the image of blood spilling from Mark's corpse. However, it was the reason for killing that still held him back.
Should he kill Mark just because he was annoyed? If he allowed himself to stoop that low, would he also start killing people for minor offenses? Noah aspired to become a monster like the Dragons in Legend or the epic boss Monsters in his stories, not a psychotic killer, controlled by his emotional desires.