Bloodbath (The Fathomless mastery) guitar tone Revalver MKIII

Hmm, I'm not too experienced at bass, but I agree the type of tone they get is fucking awesome, and I think if you were to get a Tube Screamer (TS7) and re-amp the clean bass signal through that it'd definitely get you close!
 
Marcus is right, you need to use an OD pedal of some kind (TS seems ideal for that kind of sound) on the bass high-end to get it to sound like that.

Nice progress since I last checked the thread! Though I'm pretty adamant that Revalver doesn't sound much like the tone on that album, if we're talking about the intrinsic character of the tone. Getting the bass some more mid-grind should aid you in filling out the sound somewhat!
 
For some reason this album brings to mind about 10 Marshall Plexi stacks all cranked to 11 layered up for the saturation rather than 1 amp quad tracked.