Their Bloodwhetting should probably be able to shield them through a Primal Scream cast into the Chaotic Cyclone or Primal Rend follow up at least given they don't have the luxury of like, RPR stopping everyone or BLM being able to LB outside of line of sight to stay safe. If you can't survive that short a span against a good team, that could probably use some tuning, especially because you get CC immunity for that time.
I get what they were going for with the 10% hp shield from whetting because Scream gives you more HP, but that's what, 6250 hp shield normally? 7.4k with Thrill? RPR gets an effective 70.5k HP alone if it goes in with Crest up, and it can basically retreat for free. Maybe it could be at least 8k flat like TBN given you can't put it on others. I think it should keep you just living long enough to get your '16k HP x targets hit' GCD heal to get the ball rolling, barring, you know, stepping out and eating 3 preemptive lbs before you can get in yourself.
I'm still phrasing all this in the context of CC, but outside of that I don't think it's reasonable to expect survivability or even sustained damage. The more players on the field, the more valuable Blota and Primal Rend become, after all, and WAR has always held that niche for pvp. DRK only supplants it with the new multi holmgang, but even then you can just Rend in after your co-drk drags, slapping on damage at least if they purify, and immediately breaking their guards if they don't.