5 "heroes" have prophetic dreams. In a world where reading fate is always 100% correct.
The trick is their dreams are given without context and contain lies in context.
They act on misunderstanding, they have horrible teamwork and only survive/stay/win together (in elaborate choreography) because they are literally fated to.

>Farmerboy dreams went right to his head and he became an insufferable self-aggrandizing idiot, until he is broken (realizing he tried to save the broken shield he bought instead of the she-Cleric)

>Cleric believed she had childish dreams, they can't be prophetic because she is mentally incapable of offensive spell.
>*shock*
>She's afraid of being mentally corrupted by an abomination, it turn out she use one to rewrite her own mind, twice, and become a omnimage

>Archer is on the run from an assassination and his dreams say he'll be killed by a fearsome born-assassin girl, he spend his time trying to kill her first, testing her, refuse her (poisoned?) drink, telling her he know she can fight

>Thief had her dreams portray Archer as a dark mysterious antihero (she'll love torridly?), capable of shooting arrow 5cm of her head to kill a monster, encouraging her, testing her. After learning to fight (from zero) she save him by aiming for his head

>An old veteran (traumatized by false prediction) think his salvation is to train all of them to escape their deaths. He lied on the reason and later go mad/suicidal as he realize his training led some to their near death. The Farmboy he reforged into a hero save him

The ending have them meet the sorcerer who manipulated (their) fate to extend his own life. The final involve the sorcerer making everyone transform into their ALTERNATE SELF for a few hours.
Hilarity is that the evil sorcerer also change, to a very friendly and helpful mage who deduce with horror he is the culprit, he realizes fate is like a rubber-band fighting back change, to keep the veteran alive he sacrifices himself instead.