I think they were claiming Unicorns could not become extinct and they were trapped in the water until they were freed
There was at least one human who captured an immortal animals so that they could live on forever in the animals memory because immortal animals would not forget them after they died
It seems kind of like the opposite of adapt or become extinct
@shortstories @SirSpeedBump Unicorns are like MGTOWs just leave us alone.
Also I think it's about magic fading away, a very common trope in fantasy.
Today it's the opposite we are confronted with fantasy and chaos coming back.