Xander - Abyssal Fireball Damage: 6D8 = [6, 3, 3, 5, 6, 5] = 28
So, on a failed DC 17 Reflex save, a character takes 28 points of fire damage. If the save is successful, the damage is only 14. For every 5 points of fire damage taken, the character also takes 1 point of vile damage (rounded down) on a failed DC 17 Will save. If that save is successful, the vile damage is negated.
So, if a character takes the full 28 points of fire damage, then they also take 5 point of vile damage if the Will save is failed. If the Reflex save is successful, then the character will only take 2 points of vile damage if the Will save is failed.
Red Mist: The abyssal fireball ignites the red mist, which causes those in range of the fireball to make a DC 20 Reflex save or take electricity damage equal to half of the amount of fire damage they take from the fireball. So, if a character takes 28 fire damage, they also take 14 electricity damage if the second Reflex save is also failed. If they take 14 fire damage, they will only take 7 electricity damage on a failed save. If the saves are successful, the damage is halved to either 7 or 3.
Those outside of the range of the fireball but within 10 feet of one of the campfires must also make a DC 20 Reflex save. The damage is 2d6 electricity and if the save is successful, the damage is halved. For those not within 10 feet of one of the campfires, the damage is only 1d6.
Ignited Red Mist - Electricity damage:
2D6 = [1, 1] = 2
1D6 = [2] = 2
Well, those rolls are terrible.