Kirio was known as the "Slayer of Bears" and a member of the Mosstusk tribe of Forest Trolls under the leadership of Nuvazgal at the start of the Great War.
When the trollish tribes united under the leadership of the Amani and the Trollish Army was assembled, he was given the rank of officer given his previous experience in the hunting of the great bears of Zul'aman by Nuvzagal.
He remained north with Maka's divison while Nuvzagal invaded through the south and participated in the siege of Silvermoon. After the defeat of the elven Grand Army at the hands of Nuvzagal and the Zandali expedition, during the beggining ot the First Battle of Silvermoon.
He was among the forces that where taken by surprise by the remmants of the Grand Army led by Rimtori striked. And at the impending leadership crisis it presented given most high ranking trolls where fighting within the walls of the city he was the only one to listen to the advice given by Joa'mar, the dire troll turning the tide of the battle doing so.
It was because of this actions that him and Joa'mar where promted within the army and given positions within the highest war council of the trollish alliance, alongside trolls like Ha'lin, Nuvzagal and Jin'thek himself. And so given the honor of participating in the fatidic battle for Quel'danas.