The Arathi will feature prominently in The War Within, but what do we know about this human tribe, and how are they related to the famous Arathor Empire from the past?
Like all humans, the Arathi are decended from the vrykul. Centuries ago, the Arathor empire was founded when Thoradin, an Arathi warlord, united the human tribes of the Eastern Kingdoms under one banner. This empire went on to ally with the high elves of Quel'Thalas in the fight against the Amani Trolls, who the Arathi successfully defeated.
Over time, Arathor split into the Seven Kingdoms. Thoradin's descendants moved south, eventually founding the kingdom of Stormwind. Thoradin's last known descendant was Anduin Lothar, who died a hero in the Second War.
The Arathi that we'll meet in the War Within are not, as far as we know, Thoradin's direct descendants. According to our interview with Anne Stickney and Tina Wang, this particular tribe splintered from the original empire long ago — before Arathor even split into the seven kingdoms.
Guided by a vision of a falling star, these Arathi have arrived in the zone of Harrowfall. Deep beneath the earth, this zone is lit up by the subject of their vision — a crystal sun. The Arathi that we will meet are utterly devoted to the Light, and in fact their airships are even run on the Sacred Flame.
According to the Blizzcon What's Next panel, since the Arathi's arrival in Khaz Algar, they've found themselves trapped within the zone. Every member of this society is an able combatant, but they deal with the constant threat of sea monsters as well as invading nerubians.
By the time we arrive in Harrowfall ourselves, its crystal sun will have begun to fade