The dreams in this story is a vision of a class/ path that is possible to the character in their future. It is one of their best possible classes that they can obtain, meaning that there are other classes that they can take that might be better, but generally its better to aim for the vision class,  this is the way by  to compensate humanity for its sudden change  and to allow them a fighting chance for survival as well as giving them a chance to evolve to a stronger race. The dreams show a random life form that has the class and shows them showing parts of what the class actually does.

Alot of luck is involved with the dream as it can show a strong predecessor or a weak one displaying the class, but the strong one isnt always good as shown what happened to Corrin as trying to emulate a powerful move while at the very start could kill you from the backlash. But a weak one isnt that good either as if you are unlucky enough to face a strong monster from the start the basic move wont help as shown by the dead student.

Stolen from its original source, this story is not meant to be on Amazon; report any sightings.

Although the vision is important, it really depends to how the person in question views it, and how they use it. As well as the monster being teleported in, if a weak one appears then you can survice and latter grow stronger but if a strong one appears then tough luck. Guns and technology only works on the weakest monsters as the monsters all has an innate ability to manipulate energy as a shield or Mana. 

The monster that teleported in, (the one with the scythe) is obviously a ....

author notes

A lazy author that writes on the spot as well as only releasing it as it is with no editing, im going to start working on this again along with my other fiction Yami.