if I do a double energy explosion to 2 adjacent enemies they will both take 2, ok but what if 1 has toughness, is the initial attack seperate and the splash damage 1 total attck for 2 dam, or 2 seperate attacks for 1 dam each

Does the fig with tough take 1 or 0 dam?

All damage from EE is dealt simultaneoulsy. So the Toughness would reduce the splash damage by 1.