Asheara is a lady NPC located close to the Sundered Pass, sending the player off on a quest to investigate Alcarnus to see why supplies couldn't get through.
Diablo 2
In Diablo 2, Asheara was the leader of a group of mercenaries - the Iron Wolves. They were the protectors of Kurast and prided themselves of being as tough as the jungle outside the town.
In Diablo 2, the Iron Wolves' home of Kurast was protected by magic, first by Hratli and then later by the once-powerful mage called Ormus who used the Gidbin to forge a powerful Skatsimi spell. Given this, it seems unlikely that the city could have fallen in just 20 years especially since Mephisto, the demon responsible for the corruption of the area was slain and his soulstone was destroyed. However, it is possible that Kurast never recovered from it's near extinction, or perhaps the Iron Wolves decided that their talents would be more useful elsewhere. It is also possible that since the destruction of the Worldstone meant an end to demon attacks, that Asheara had to change businesses.