Cho'gall is the final boss of the Bastion of Twilight. He channels the power of the Old Gods and is not to be taken lightly.
The reason for the second tank will become evident when Chogall uses Fury of Chogall. This debuff will essentially make him un-tankable by whoever is hit by it. What can be done is have the off-tank taunt Chogall right as he is about to use it. This way the off-tank will eat the debuff and the other tank can taunt back and resume what he was doing without worrying about doing a tank switch!
To read the latest guides, news, and features you can visit our World of Warcraft Game Page.