Zin'jun is a trollhunter serving under the command of General Nazgrim. He, along with various Horde heroes and his trusty companion, Snuff, take the trip into Pandaria aboard Hellscream's Fist. It seems he was knocked off the ship during the initial battle with the Alliance, as were several of his comrades.
Zin'jun landed at or near the Ascent of Swirling Winds in the Jade Forest. He and his tiger were attacked by hozen, Snuff killed and Zin'jun's eyes taken from him. When he recovers his belongings he quietly dies inside the nearby cave, thankful for the help players have given him.