Zechs had already figured that Natsuno wasn't like anyone he'd encounter in his own reality - even those enhanced like Heero Yuy had been. But he wouldn't begin to guess at his nature, given how weird the realities the train's passengers could be.

"That's all you really need," Zechs told him honestly. "A drive to succeed and improve yourself. I'm glad to see it."

Instead of the defeatist attitude he'd witnessed other times, when they were on the train itself.