User blog comment:Derax-Pagani/Chapter 509: Kagura vs. Larcade Review/@comment-7418318-20161107191643/@comment-5303512-20161108195936

This is just a theory, perhaps Mavis' curse was somehow transferred from her at her death to Larcade, that is why she hadn't killed anyone yet nor was she healed like Zeref did, and we saw the eyes changed like Mavis and Zeref.