User blog comment:Woest/Raven Tail/@comment-4829046-20131119155845/@comment-7418318-20131119162805

Even when I point out that something is unlikely, I never consider it impossible untill it's proofen wrong. ;)

But assuming that Zeref knows about Lumen Histoire, I think the lack of information that Ivan had indicated that Zeref doesn't want Ivan to have it and only told him the name for some other ulteriour motive.

If Zeref knows as little as he told Ivan, it might have been a scheme to gain more information about it, like it's actual nature, though that'd be a great risk, chancing a person like Ivan to gain control of such a protentially powerful thing.