Why do white and blue mobs deal 99,999 damage? Is there a 100k HP guide?

1.7k HP, 1.5k energy shield, and 1k mana — that's a total of 4.5k effective life. Resists are capped too, but they still one-shot me.

The Vaal Factory traps one-shot you — I think it's the mosquitoes coming out of the blood, but they're so hard to see I can't even be sure. They just one-shot.
There’s also this mushroom-looking thing — instant death. And some vases that pop up from the ground and move — also one-shot.

AND YOU CAN’T SEE ANY OF THEM. YOU JUST DIE. ???**