Dark aeons come in the world after you've been to Bevelle. The people who have them unleash them because they think your a traitor to Yevon. But the worst thing about Dark aeons is that they can use there Overdrives whenever they want and they have like 3 turns in a row. So you need a powerful move to finish them off in one go.
Dark Valefor
On your entrance to Besaid village.
Dark Ifrit
At the Al Bhed "HOME" after first visit.
Dark Ixion
Thunder plains, talk to the knight near one of the lightning towers.
Dark Shiva
Entrance of Macalania temple, after first visit when you killed Seymour.
Dark Bahamut
The place where you fought Lady Yunalesca.
Dark Yojimbo
Go back to the cavern of stolen fayth, teleport inside it. Then walk back, a man and Dark Yojimbo will appear.
Dark Anima
Mt. Gagazet, the place where wakka had to throw his blitzball. Complete it again then go back to the entrance of the cave, Dark Anima will be waiting there
Dark Magus Sisters
Mushroom rock road, walk past the boy and woman and then just let them catch you. But if you want a chance to run away, Run to the route you took before. Now go up the elevator. Now run as fast as you can, If the screen flashs yellow it means that the magus sisters are near and if its red it means there right behind you.
