Rob

Rob is a Fairy Tail mage, who was kidnapped and enslaved in the Tower of Heaven. He was also one of Makarov's and Erza's close friends.

Tower of Heaven arc
We meet him as an older man who took care of Erza and her friends on the Tower of Heaven bulding. It was he, who taught her the true meaning of "magic". He died during the slave's rebellion, protecting Erza by his own body from a magical attack. After this incident, Erza woke up her magical potential.

Magic and Abilities
Fire-type magic: In Anime Rob used a fire-based spell to protect Erza.

Trivia

 * Rob has a large Fairy Tail symbol that cover his whole back.
 * He was formelly in Makarov's team.