Why does no one remember Gildartz? During the Battle of Fairy Tail, no one mentions the S-Class wizard, Gildartz, when suggesting who is the strongest. Why does no one remember him? Do they assume that he would be on a mission that would take too long, and would take perfect timing for him to show up?
He is mentioned. In chapter 119, Mystogan mentioned him to be the strongest of Fairy Tail and I quote:


  Mystogan: I have little interest in such things, but I would propose Gildartz.
  Laxus: Eh, he's no use... He ain't coming back.


Presumably, Laxus knew Gildartz was undertaking the 100 year job involving Acnologia and had assumed him to have died, since no one else has ever come back from that mission alive.