The Arcanist class has been announced to be a new magic based class with a focus on crowd control and support abilities. The class will make its debut at the launch of FFXIV: A Realm Reborn.
Adepts of the art of arcanum derive their might from symbols of power born of geometric techniques hailing from across the southern seas. Held within occult grimoires, these symbols lend shape to the arcanist’s aether, thereby allowing him to produce myriad powerful spells.
Using the selfsame symbols to unlock the latent power contained within gemstones, arcanists are also able to summon forth the familiar known as Carbuncle to carry out their bidding.
By completing quests the Arcanist can become a Summoner and a Scholar. Summoner will give it access to miniature primals to summon called Egis while scholar will have a fairy pet.
As an Arcanist you should be focusing on INT as this increases magic attack power.