The Corrupted Temple
The Corrupted Temple is a zone in the Rain of Fear expansion. It is an instanced raid zone version of the north wing of Temple of Veeshan. Most dragons within are intended for Tier 2+ VOA raiding guilds. Vulak'Aerr however, should present quite the challenge for even the toughest of adventuring guilds.
This zone is linked to Western Wastes.
To enter the zone and begin a raid, head to Western Wastes (Velious). At the entrance to Temple of Veeshan there is a purple crystal. Clicking the crystal will spawn "a temple custodian". If you have between 6 and 54 people in your group/raid, you will be assigned the raid instance upon telling the NPC "enter". Once you have the expedition, say "ready" to enter.
Lore
The Temple of Veeshan has been corrupted by the falling shards. Sontalak, being the inquisitive guardian of the temple that he is, saw the shard as it fell into the canyon near his watch post, and dragged it back inside near the portal. Inside the crystal, the north wing of the Temple of Veeshan has manifested with familiar faces, yet somehow they're not quite the same.