Kitru I want you to take this as constructive criticism from a viewpoint of someone who's familiar with most every job in the game. REV/DRK pretty much carbon copies the best between WAR and PLD with souped upped abilities from other classes and higher DPS, and frankly seems way too OP and lacks something that really sets it apart from either PLD or WAR.

-Basically you give them an easy to maintain no drawback version of Defiance along with it's own version of Sword Oath so they can maintain an average 20% phys mitigation, 30% magic mitigation, along with a 30% HP boost but only 20% in damage loss.
-Dirty kick by far has the longest lasting effect and shortest cooldown of any Non-GCD stun in the game.
-Cripple has a ridiculously short timer, you could realistically maintain heavy and kite targets with ease all the time.
-If Exultant Swing is kept up Souleater's negative effect really isn't a drawback, and assuming Blood Sacrifice wasn't just poorly worded you can just pop that prior to using Souleater and reap it's benefits without any loss.
-After factoring in traits all the drawbacks are really minimized to almost negligible proportions when stacked with other abilities.

I also have to ask what cross classes were you considering for this job?

-GLA/MRD abilities would probably put's it's average mitigation close to PLD considering the extremely short cooldowns and trait effects on Pacts.
-Giving more than one PUG/LNC/ARC DPS buffs would prolly put DRK's DPS on par with well other DD's at least outside of Shadow Ward which just craps on tanks and DPS jobs in general having both damage, survival, and some self sustainability at their disposal.
-While ACN/CON might have limited ability uses for non-mage jobs Virus and Eye for an Eye are pretty powerful in their own right for mitigation, and Stoneskin topped with Exultant Swings effect is a pretty decent E-hp buff in a pinch or between fights when mages are trying to conserve mana.
-Really THM is the only thing REV/DRK wouldn't get much if anything out of it.

That's all I really have to say about it. I'm not saying it can't work but it needs some solid fine tuning, because the only real tradeoff on all that DRK is getting is the 20% reduction from Shadow Ward, when in turn it basically get's near PLD survivability, better than WAR HP, some self healing capability, good AoE capabilities, better DPS than either of the two jobs and factoring in cross class possibilities will only improve their standing.