|Unlocked by achievement|
Sister of the Thorn
A one handed axe.
High Damage, Armour Piercing, Shield Breaking
You unlock the recipie by completing all the "Back to Ubersreik"-missions as Kerillian, on any difficulty. The missions are a part of the "Back to Ubersreik"-DLC.
You can complete the missions from "Back to Ubersreik" via quickplay or via joining a friend who launches those missions for you. If you complete the missions and take a look Orik's challenges, you can see you have progressed. HOWEVER, if you haven't purchased the DLC, you cannot claim the recipie once it becomes available.