Mark DeanCalling it now Dead Rock is a prequel to Fairy Tail.
Yakuto is Acnologia.
When we first meet Acnologia, he is a doctor with no name and no real memory.
I feel like this will fully explain why he can revert back to a human in Fairy Tail
Sevro 
So, #HiroMashima’s new #manga #DeadRock has #Viking themes in it and I’m so fucking here for it. I cheated and read it early and feel guilty, but I’m DEFINITELY going to buy it when it comes out.
The Fandom Post
Universo Nintendo#DeadRock es el nuevo #manga del creador de #RaveMaster, #FairyTail y #EdensZero, el cual ya tiene fecha de estreno :3. https://tinyurl.com/ys9n52p2
