I have finished this novel. My initial response...Malgus' character is dynamic throughout the story. Constantly changing. I am lead to wonder about his upbringing as well as his origins. He loves his violet skinned Twi'Lek Servant more like a wife than a servant. This does not go unnoticed by the other Sith, however.
Also, the siege on the Jedi Temple is a little different than the "Decieved" Trailer. Rather than his Narrative ending with "You...were decieved, and now your Republic shall fall", he says to Master Zallow "It's all going to burn".
He is a dynamic character precariously held in the balance. Make no mistake, although he serves his empire, he has his own vision and lives for war and conflict.
Story wise it shows the rivalry you would expect from sith lords in an inner-structural inner-circle political sense. This won't be the last time I say this: Malgus (as I predicted if for no other reason than his similarity to Vader) will in all likelihood be a pivotal character that you may end up recruiting regardless your mission/allegiance. I was sure of it before and now I am almost positive.
Whatever your choice, I am sure you will run into Malgus if you are a Jedi/Sith character.
Suffice it to say this much: This story also reveals the antecedent roots, and bloodline, of the Korr namesake (Jaden Korr, jedi knight academy). To an extent the origins of the Xizor name (Like Prince Xizor, though not his family) also are revealed.
Any Carth fans out there might want to get this novel--I think FemRevXCarth fans would like it. I'll have more in my Review.