Yes, he knew the ghost around him well. The strongest ones he had already broken down. With different methods, of course. It was easier to kill things if you knew how they had risen to power. But he would remain silent about it. If people wanted to save them, they would be welcome to fail.
"I agree. Besides, sometimes you have to sacrifice some to protect others. I would not hesitate to kill them all if it gave me the skills to keep people like you safe," he said while he scanned the area around him. The softness of his words stood in contrast to their cruel content. Yet, for him, it was no contrast. It was just part of an unfair and ruthless world. You doomed yourself if you held empathy for every creature around.