So, God Serena is dead. Acnologia stronger in his human form then I thought. With the final battle just around the corner, I wanted to share my opinion on who would last long against the Dragon King.
1. Cobra/Erik - I know he's not as strong as God Serena, but his hearing would actually give him an advantage. He'd be able to evade Acnologia's attacks.
2. Natsu - If Natsu is as strong as Gildarts now, I think the Salamander could hold his own against the Dragon King like, metaphorically, a black bear would against a grizzly. If Natsu still has those Fire Dragon King spells, those could do at least some damage to him. Acnologia could smell Igneel's scent on him and decide to get back at the Fire Dragon King, by beating his son to death.