The problem is that generally players tend to let a storm snowball with 5 Champions (and if your RNG is really that bad, 3 Shrikes or Bloodknights running around) because they don't know mechanics, and that's when the storm really gets punishing.
If theres a way to stop 5 or more champions from showing up since ghosts have become invincible, I still havent found it yet.
That sounds like a nasty bug; at the very least I don't see it on PC. Might want to raise a bug report for that.
On a side note, are they "can't die" invincible or "untargetable" invincible? You could possibly try snare stacking to slow them down, but you'd need a big group to clear it since it's a delaying tactic at best. Best to get it fixed.
Yep it is a nasty bug, I reported it back in early June. And its on PC.
Id say its more of an 'untargetable' one I guess. I can slow them down for a second or two, but after which I cant even do that anymore.
I made a quicky, sloppy video back when I reported it so can see whats going on.
https://youtu.be/KvM86UiKe34