Props to Tarkhan for his redo- that makes more sense then the random roll. Love the backstory part- i can see some potential there. A few things:

1: 50 years training? too long. Nobody but an elf is willing to devote that kind of time. Also, you said human don't live long enough to become one but half-orcs make good candidates? Half-orcs live to be about 60.

2: What specific domains does Khaine promote? I'm thinking Courage, Death, Destruction, War.

3: D4 hp? If the character is even going to say the word melee he should have at least a d6. A d6 assumes that while yourcharacter is fighting they won't be hit to often, like a rogue. "get in, attack, get out" Incorporate a feat like spring attack, so they can use their high speed. D6.

4: Blood- they're is a huge story focus on it, but no related skills. Why not? Work in some blood juju or bleeding attack, whatever. It's your character, what seems appropriate to you?

But seriously, good work. This class has a unique flavor do it, and it tastes good.

P.S. The Tau own the Necrons.