During an evolution, one would usually find themselves in a state of unconsciousness, during the early stages, before the warrior realm, an evolution would have them be almost asleep, sometimes they would see visions, visions that were made by their abilities, which would allow them to get a glimpse of what the ability could do in the future.
But when one got to the higher realms, that usually changed. Each Tier that a person tried to break would be a dangerous endeavor, needing full concentration from the person that was evolving in order to pass it.
One needed to hold on to their sanity sometimes so that their soul wouldn't get damaged or destroyed, sometimes one would have to face nightmares that would disrupt them, while at other times, one would actually need to go through a battle in their mental space. Nobody knew just what would happen during an evolution, but one thing was certain, the higher one went, the more dangerous it became.