Erik

Cobra is a mage which belongs to the Oracion Seis guild, a dark guild composed of highly powerful mages. He along with the other goal is to find power know as Nivana, a very destructive power that was seal away long ago. As his name suggests, he is a mage who like to use poisonous snakes as his weapons. He also has the power to "hear" things which he able to decipher information as well as movement from his opponent, which is how he was probably able to hear about the alliance the other guild were conjuring against the OS. He, along with his group, attack the alliance consisting of Fairy Tail, Blue Pegasus, Lamia Scale, and Cat Shelter easily decimating them. His target through the battle is Erza who manage to hold her own against him. However Cobra manages to "hear" her movements and uses his snake to bite her arm. Poisoning her though he mention it won't kill her outright just very slowly.