Try stacking Solar Resist and Melee Resist if you're having problems in round three, you can also throw on a Void resist if it's the first two rounds that are giving you problems. I've also found that weapons with good ad clear are a godsend in Altars; Chain Reaction, Volt Shot, Incandescent, and Destabilizing Rounds put in work; fewer surviving enemies means fewer enemies hitting you. I'm guessing from the stacks of Frost Armor that you're playing Titan; as a Warlock I can't give you a ton of advice, but if you choose to pick up Warlock I've found that that Buddies are extremely helpful, they shoot things you can't even see, and Vesper of Radius' AoE explosions will help keep enemies off your butt. (Blind and Amplified are super helpful; if an enemy can't see you, they can't hit you.) As Bore said below, Health is more of a PvP stat, it's really useful when you can find a corner to hide in for a second, but not so great when you've got waves and waves of enemies constantly closing in on your location. You [i]might[/i] be better off putting points into Weapons and using a gun with good ad clear, but that's going to depend highly on what builds you like to play. And, for what it's worth, there seems to be a small element of randomization to the difficulty; I can often go three Altars with no deaths, then get absolutely walloped in the fourth, maybe it has to do with spawn placement or something, I don't know, but what I'm saying is it's normal to get knocked down from time to time, even with a good build. I believe in you, you can do the thing! Oh! And make sure you're shooting the Shrieker before you try to Invoke Hive Magic, those dudes have a k/d ratio that's off the charts. Disabling Shriekers saves lives.