Warhaft was mentioned after Arena. Small bit, pre-OBL.
pre-Morrowind as well, unless there is something else...
From this: http://www.imperial-library.info/obscure_text/forum.shtml
Nohept dir'Kamal : Source of Chaos- Serious Scholars Only
My dear General Warhaft,
I found this particular passage among the papers of the Tharnatos.
"...appropriately, Padomay is just as ineffable an entity as Anu. This is how the Psijiic Order treats him, at least. His original (Aldmeris? Ehlnofex?) name is PSJJJJ, which is and was meant to be unpronounceable. The Order was founded and organized to divine Padomay's eternal and ever-changing mystery. "Sithis" is a corruption of "Psijii" which, in turn, was a derivation of the high concept PSJJJJ. Sithis was born when a nihilist sect of the already doom-ridden Chimeri merged (under Mephala's tutelage) Daedric elements with the Inexpressible Action that was Padomay. In essence they began to revere Padomay's Chaos nature (as opposed to that of Anu, who is Order), and over the years degenerated into a thuggish mystery-cult which wanted to "murder the world." The Dark Brotherhood was born in these times-- which, in Morrowind, is known as the Morag Tong. Some of the higher-level Morag Tong maintain that they predate the Dark Brotherhood (more evidence of this later). That, in fact, they are an organization devoted to playing out the eternal interplay of Nir. Assassination, they say, is the purest celebration of joy or living. Whatever the case, the Padomay of Morrowind (and isolated Dark Brotherhood sects) is not the Padomay of Artaeum...."
Does this help your investigation at all? Are all the simulacra accounted for?
Ever your servant, Nd'K Cult of the Ancestor-Moth
Lady Enigma : Information taking in, routed, and distributed to nearly any sector that could make anything of it. I cant believe that I understood most of it. The main lesson learned is that the Morag Tong, are some BAD mothers, and you should kiss their boot anytime you can, tee hee hee.
Lady Enigma
General Warhaft :
Elder Nohept,
These scholarly conundrums are outside my expertise, I'm afraid. I have uncovered nothing explicitly tying the Morag Tong to Tharnatos, but my suspicions grow stonger. They have long been given wide latitude here, rationalized as "non-interference in local customs". You would be amazed at what is permitted here. But I digress. The Tong are difficult to infiltrate or investigate quietly, as they are insular and extremely paranoid. Beyond the obvious link of the Staff to House Redoran (which has turned out to be nothing more than local scheming -- they knew nothing of the larger picture, as I thought), my agents have turned up only rumor and hearsay.
As for the simulacra, at last report the Blades were on the trail of the last three. I continue to hope that one of the nephews may have avoided the fate, and flees now from rumor of a purge. But I must say that Andrial is less optimistic, and knowing Tharnatos' thoroughness in other matters, I fear she is right. There is also the possibility that some may have been secreted like we were, as pawns for some future play we have not yet uncovered. You would be more up-to-date on those matters, however.
It is vital that you learn his true identity. We cannot fight enemies we do not know, and even he may yet prove only one actor in a great conspiracy against us. Reply soonest.
Warhaft
Sounds to me that either he is a Blade now or he is working with them, but either way it would seem he was in Morrowind last, which explains why he was no longer in Cyrodiil.