User blog comment:Lex wa Kaiho/What is Lumen Histoire?/@comment-26399354-20130627162312/@comment-4829046-20130627163042

No, they are just there because Mashima likes having all his favourite characters in FT, they have been appearing since the start of the series. Even though there is a FT X RAVE story, it is only a joke sequence so shouldn't be taken seriously.