For the most part. Zeref wasn't out for blood; he wouldn't have even considered doing this if he didn't think Natsu could handle Nemesis. After all, compared to what he was fully capable of with Living Magic, Nemesis was almost an entry-level Living Magic spell, just a few steps up from 'Alive.' If he were REALLY getting serious about this, he'd have created a real monster, not unlike Deliora.

So... He knew this spell. Figures. Plenty of Dark Mages were Zeref wannabes. Something he had grown to resent during his time on Tenrou.

"Hades was a delusional old fool who believed he could control my magic better than I, myself can," Zeref said quietly. "His death will be one of the few I won't mourn." before pointing his finger forward. The Nemesis constructs converged. And... they were fast.

Indeed, created from someone like Zeref, these monsters were moving with an preternatural talent. They were faster, stronger, much more coordinated than anything Hades created, moving with the predatory instinct of a pack. Natsu had better react quickly.