that's the basic hero that can be recruited in the frozen throne expansion
But apart the basic campaigns, there is a "smaller" orcs campaign that's about the founding of Durotar Nation, using Rexxar and other characters including Chen.
However the campaign had to be "updated", dowloading the other parts from the Blizzard sites to ends it.
It ends with the Horde attacking Theramore and killing Jaina's father ^^