I'm probably gonna piss a bunch of people off here with these SS, but seriously...

After you kill Ifrit, you open the chest and you randomly get 1 of the 7 weapons. It doesn't go to loot pool so that people who can use it can get it. It isn't determined on what jobs you have leveled. It's just stupidly random.

http://www.gwcdn.com/albums/images/4e96593289118b6df10079b4.jpg

I'm a mage. Let me get a mage weapon. I've killed Ifrit over thirty times and I'm getting DoW weapons. Not the ones I can use. Come on...