Having trouble finding Dre?adnought...

I am looking for him also - so i eagerly await an answer to this!

With the skills [more enemies] and [attract tougher foes] it shouldn't take that long to find this guy, but if you are having trouble i would suggest that you run the full length of the map several times and be patient.

after doing this method i ran into the dreadnought more than 10x and managed to get a blk chocobo in the process along with yakshini.

If you have Battlemania AND Encounter Master both activated. He should be in Vile Peaks 010AF (the path you can only get across in this time frame) i caught up with him at the end of the top path JUST BEFORE you jump back down to ground level. Hopefully you guys find him! :)

I'd hang around the enclosed tunnel area at the beginning.
That's where I ran into him and Black Chocobo pretty frequently.

Vile peaks -010AF-

Head north and there'll be a tower where you can you left and right before descend to the place where you'll have to fight twilight odin, but before the tower, there'll be a route that is near to the shape "U". Go back and forth along the "U"-shaped route (With one of your fragments skills, i think it's battlemania, set to more enemies)