I think the 'Doom Upon All The World Achievement' is glitched on XOne. I defeated Corypheus and his corrupted dragon, watched all cutscenes and waited until the credits have rolled but the achievement did not come up, which is somewhat frustating. Did anyone else have this problem? If so, did you manage to fix it somehow?
There's a similar error for the dragonslayer trophy whereby if you're controlling a follower instead of your main character at the instant the 10th dragon dies, the trophy doesnt pop, but does if you reload, refight and switch back in time.
In light of that, by any chance were you controlling one of your followers (say, vivienne) when the final cut scene chain begins at the end of phase 3 of the boss fight ?
I was controlling my main character when I finished fighting Corypheus but I have loaded my last save point prior to the battle and fought him and his pet again. This time I have got the achievement. I don't know what happened before but it's all good now.
Thanks.
