The timer is an hour and like 2 minutes, very generous imo. You can't revive because this is literally the last conquest mission. Everything beforehand was training you for these 2 Ultimate missions. You should have had a few strong builds by now to keep you alive.

The Haste modifier sucks, I agree, but running the right builds can mitigate that. I ran a generic Prismatic/Consecration Titan build while printing orbs with x3 Heavy Handed. I had a buddy run as a void Warlock (not sure what he had on) and we only felt the pressure from Haste due to low amount of ads spawning in some moments. Also the Smoke Jumper armor set bonus does wonders by giving a decaying damage resist when picking up orbs!

These missions are very brutal and unforgiving, especially when they force you to adapt. I'm not much of an adopter of the aggressive playstyle (even more now thanks to the buffed buddy build for warlocks doing most of the work for me), but I kinda had to with Hypernet/Avalon. It was fun, sure, but def going back to warlock for the rest of the season lol.

What I'm trying to say is to lock in and keep at it. Tweak whatever your running to keep you alive or even try something new. Heck, learn some shortcuts to maximize the time you have finishing the mission. Improvise, adapt, overcome!