i know a little bit of the backround from IH and DC but does anyone have concrete information on what exactly the Empty Men were? i know they were a xeno genetic creation by the logicians but in what way?

There's some information on them in Damned Cities as they were a recent event on Sinophia. The short of it is that the Logicians were experimenting on the local PDF and splicing them with xenos DNA or something to that effect. Most of the subjects died or went berserk, Inquisition purge was called but it's suspected that the Logicians got away with some prime test subjects. It was a publicly known event, so random Sinophians may talk about the Empty Men.

Obscure fact of the day:

Sinophia was the setting for several Inquisitor (the old GW game) missions run by one of the DH authors and many of the events in DH "recent history" are from these game sessions. I seem to remember reading a bit more about this at one point but am not remembering what or where at the moment... Sorry. Pretty sleep deprived from work ATM. Might be able to scare up more info with a little websearching.