Ahhh Fairy Tail, easily my favorite manga series along side One Piece. I would love to show my interest and hope to participate. Now from what I understood from your post, you only wanted the type of magic that our characters plan to use but if I'm wrong and you want an entire CS then please let me know and I shall rectify it.
As for the magic, my character would use Puppet Magic. By putting some of his essence into one of his creations, it would give the construct animation controlled by the caster as long as the link between the caster and the construct was kept up. The amount of essence determines the strength of the puppet. He would obviously use them for combat and other needs as he sees fit. Limitations would be that the puppets are limited to the caster's creativity and that without the essence they would be utterly useless. Also if the caster overexerts himself by infusing too much essence then he would pass out or possibly die.