The players will come across a dieing oasis nestled in the valley created by 2 large dunes. The water is almost entirely gone and alot of the plantlife here has dried out and died. As the players make camp, a monster begins stalking them. I am not sure what the monster will be yet (something cr 6), but I know it will need to have a fire ability like fire breath.
As the battle insues, the monster tries to use hit and run tactics for the first half, bealching flame upon the players before returning to the saftey of the tall dried grasses. Once a good portion of the oasis has been burned away, or whenever I feel the time is right, the monster will go all out against 1 player untill its gone and then it will try to hide again.
The part I am unsure about how to do involves the burning of the grasses. As the smoke from the fire begins to fill the valley, I want the players to become rather heavily effected by it. Perhapse they start viewing everyone as enemies, perhapse they see more monsters then actually exist. Should I roll to detirmine effects? Individually or as a group?
Any sugestions will be greatly appreciated!