User blog comment:WhiteArmor/7/7/777/@comment-95.154.11.60-20140119123901

All the Dragon Slayers are more than 80 years old, that is at least a fact since they couldnt cross the barrier that said that only people under 80 may leave in the Laxus arc. Zeref knows Natsu, so it has something to do with the past. Maybe the dragons fought Zeref, but couldnt defeat him, then raised children to defeat him way back in the past, got attacked by Zeref again and then used some kind of magic thats the same as the one on the Guilds Island. Layla then found the dragons and their kids and by the time she found them, the dragons had fused with the children, and Layla knew that she would have to dispell the magic which killed her in the progress.