Bro, I don't have tomb of blood. I got black crusade, yesterday in fact. (good god is it cooool!!). I'm reading character gen right now so I can make Silas and it says the total xp for a starting BC pc is 7000. This 7000xp includes the 1000 xp we are supposed to spend. Is the 4500 xp your talkin about on top of that? If so make your guy and then buy him down an see if ya still think he's still ta play. (lol. I just figured out his tribe digs Khorne… That's awesome. .. Welcome brother!)
As for Silas. After reading some of the character creation sections I have to say there will undoubtedly be some slight modifications to Silas's backstory. I think I can use the Psycher character archetype in the BC core book to stat him out just fine. In fact I'm sure I can stat him out with just the BC core. But.. There might be minor adjustment to his story as a result. For instance I was reding about how your alignment to different Chaos gods may change over time. So starting out Silas is most attuned to Slaanesh and Teznich (autto correct sucks). But to play it safe Silas has tattoos that celebrate all the Ruinous Powers with graphic depictions of acts and incognito symbology. Such as orgies for Slaanesh and skulls for the skull god… But while each tat is by itself just kinda foul, nothing is unequivocally a symbol of Chaos. But the overall effect is still striking.
Silas should be ready in a day or two.
Yeah, seems a lot of people don't have it. Tome of Blood is an excellent splatbook for combat-oriented characters. I'll quote what it says:
"The Human characters are both roughly equivalent to a beginning Human Disciple of Chaos with an additional 4600 experience points. See pages 48 and 50 of the Black Crusade Core Rulebook for starting abilities for Chaos Space Marines and Human Heretics."
I think to really make a fear judgment call, I'd have to show the exact abilities to the GM, and then buy down as he thinks appropriate. The people of Xurunt revere a bloody god known as Baphtar, who may or may not be some manner of Khorne daemon, but is similar enough in theme that it is safe to say they begin play allied to Khorne.