User blog comment:Stone Roger/Natsu and Zeref have somekind of relation?/@comment-101.174.197.171-20140430072854/@comment-123.231.120.23-20140430110651

Unless being in Edolas triggers something else that is. His magic is vast and unpredictable so I think he will be able to do something intentionally or unintentionally without having to use his body's magic.