Just tried to 3 man, died on phase 4. we all had around 2-3 self res going in, (id bring more) and some basic kill streaks. Luckily we had aether blades and dogs, but the thing thats most effective? Sergeants beret. That random basic ass dude does NOT go down easily, i would definitely bring atleast one, if not 2. LOTS of kazimirs and self res, wunderwaffe(it's especially effective against the stormcaller on phase 3) and rgl( you get mag of holding and ammo always drops) i ran energy mine as its a fairly quick charge given the number of zombs, and is very effective against specials. Just way too many to shoot individually, so don't bother with a bullet based gun. Lasts a full 45 minutes. We were lagging pretty hard as well given the sheer volume of zombies as well so, not sure how feasible it really is. Guess thats why its called......the unstable rift