I’m testing this in Legacy at 460 corruption. I can clear normal echoes fairly easily. Can certainly get blown up if I’m careless but it’s not really hard.
This echo is near impossible. There are 3 champions at a time plus two omens. Two of the champions get that crazy damage reduction buff from the omen that makes them have something like 5x effective HP. Between champion affixes, whatever the monsters normally do and two omens I barely have any time or space to stand and cast. Unlike the well designed recent boss encounters, all of these effects are quickly lethal by themselves.
I manage to kill a set of 3 and another spawns, then another. I realize the bar is maybe 20% full at this point, so, what, two dozen total or so? I eventually can’t keep ahead of the FX spam and die. Try it a few more times and give up.
This echo is harder than Fading Brink. By a lot. And it says “Tier 1” so I guess it gets worse? If this is the intended difficulty, it shouldn’t be getting automatically placed by echo chains.
I’ll try it later on a character that’s at lower corruption and see if it’s a scaling problem or it’s always like this.