Nana Asta Deviluke has your typical super human abilities. She is actually pretty strong, but to be strong enough to stop someone like Zeref you need really special abilities. He’s immortal and has enough power to take down the planet. He drains life just by existing and that’s a good passive effect. Zeref’s definitely too fast for Nana to keep up with and while she has a lot of durability, she’s definitely not going to stand up for long against this level of power. Zeref wins.