I'd like to apologise for the use of the amnesia trope with Khalen and I do find it a little distasteful myself.
That said, it occured to me that if Khalen still had knowledge of all his previous memories, deeds, actions, etc then the second ring (and possibly third ring) of the Torment Engine would have completely failed in its task. Oh, doubtless there's probably some way to fill in the gap in Khalen's head but he's only just emerged from 50 or more years of agonising torture, so being a little brain scrambled is only to be expected.
I haven't forgotte Reveaw-Na's little message to Khalen, nor the thing I need to do with Contragh. Stay tuned.