First off welcome to sleeper's tomb! There are six items you need in here to complete the progression.
Recipe :: Proof of Pwnination - Sleepers
Now combine all 6 items in your Universal Assembly Crate to create Proof of Pwnination - Sleepers and hand that in to Borat in sleeper's for your Shroud of Kerafyrm Rk. 1.
To upgrade this, you will need to combine two Epic Gemstone of Immortality in your Universal Assembly Crate to create a Perspective of an Immortal. Then combine 1 Epic Gemstone of Immortality with 1 Perspective of an Immortal in your Universal Assembly Crate to create an Overlords Anguish Stone. Then combine 1 Epic Gemstone of Immortality with 1 Overlords Anguish Stone in your Universal Assembly Crate to create an Epic Sleepers Stone. Then combine 1 Epic Sleepers Stone with your Shroud of Kerafyrm Rk. 1 in your Universal Assembly Crate to get Shroud of Kerafyrm Rk. 2. Continue upgrading that way until you get rk15, which is called Epic Shroud of Kerafyrm.
Tactics
Pretty much all tank and spank. Watch out for Kerafyrm, he hits fast and hard!