So, under certain circumstances, Uber Lilith will do her Spike Wave in Phase 1 back to back, never ending. All enemies dead, and there’s nothing you can do but dodge until you finally die. There’s basically no chance to damage her because she touches down for half a second and then flies again. It occurs in one of these two circumstances. Not 100% which but I and the group I was playing with narrowed it down:
1: You stagger her before she even starts sending waves of spikes out (the ones where two go one way and the center goes the opposite), or
2: You kill the two Enforcers before the Spike Waves even occur.