After I beat the Elite-4, I can't seem to find Drilbut in any dust cloud, I only find Exadrill. is Drilbur gone forever?
Just check these areas:
Wellspring Cave Chargestone Cave Mistralton Cave Twist Mountain
You should be able to find Drilbur in those areas. Other than that, it is all Excadrill.
No, you can catch it in Twist Mountain,etc.
Post-game, wild Drilbur does not appear in new unlocked areas, only previously explored ones.
Source : This Site, Personal Experience.
