"What was more important?" Batman couldn't imagine many things more important than dealing with a murderer. The few times he'd left a body behind, he'd usually regretted it. At the very least, it made him wonder about Schuldig's priorities.
"You know more about Kira than that." Exactly what he knew, Batman couldn't say, but he was sure he did. If nothing else, he worked for one of the men in question; no sane bodyguard would take a job for someone without understanding why people might be after him. And for that, he'd need to know more.