Anyone with a character pre mediah questing can open up their quest log and scroll down to see this. Upon starting Mediah this disappears.

This quest line includes Tinyas Trust which us a pre req in further upgrading your offhand and also Co Op awakened black spirit which is required to start Ilzeras Threat.

Ive played 4 characters, taken every crossroad path and still it disappears 

So does this mean it incompletable? 

For. Now yes