Basically lifted directly from Bravely default, the idea is kind of unique.

It's different enough from typical FF5 Blue mages that FF14 could embrace it as something new. Yet since the name was used in Bravely Default though worked differently than bluemages in previous FF games, the way its done in FF14 could make it standout different from Bravely Default as well.

I know a lot of people immediately groaned and rolled their eyes at the mere mention of "Vampire", but think about it for a second, in certain fantasy universes when a Vampire consumes another vampire completely it is known as "Diablerie", you gain that vampires generation or lower your own, and more importantly its power. Now FF14 doesn't have to borrow all that, but the concept of this Fake Vampire job, that absorbs a bit of life from a creature and gaining a trait, power, or access to some of the jobs more noteworthy abilities, is like a more indepth version of Blue Mage. We've had Bluemages who've eaten monsters before in the past, Quina for example, and did anyone else notice that Quistis last name is "Trepe", it's one "s" short of being identical to a famous last name used in the Konami series Castlevania as the surname for Alucard who's father is none other than Count Dracula?

A new DPS role that merges with some of the blue mage skills, combined with a more deeper lore. I this could be the unique spin on the job that it needs to make it standout as not just another reiteration of the job, but something potentially surprisingly different.