Should Korrak the Bloodrager make a return to the Field of Strife, seek him out and destroy him.
Return the Skull of Korrak to Lieutenant Haggerdin in the Hillsbrad Foothills.
There's something not quite right about all of this... Did anybody think to burn Korrak's corpse? Those trolls will stop at nothing to revive their fallen leader - as blue skinned pagan man-beasts often do.
Just keep your eyes out, <name>. Don't be alarmed if Korrak makes a surprise appearance; and if he does, I want him executed - his corpse burned to ashes.
For good measure, lop off his head and bring me his skull before you ignite the lifeless mass.