For the Thai chile simple syrup: In a small saucepan, add the sugar and 2 cups water. Bring to a boil, then let simmer until the sugar dissolves and the color darkens slightly, about 5 minutes. Add the chiles and remove from the heat. Let cool completely, stirring occasionally. Remove the chiles.
For the sweet and spicy mango lime punch: In a large pitcher, whisk together the mango juice, orange juice, lime juice, vodka and ¼ to ½ cup Thai chile simple syrup. Place the grenadine at the bottom of each glass and fill with crushed ice. Pour the punch into each glass.
Dunk the tip of a slice of dried mango into the liquid, then into the chili powder. Make a slit in the mango on the bottom so it can be attached to the glass. Repeat to make mango garnishes for 3 more drinks.
Garnish the punch with the mango, edible flowers and fresh sprigs of mint.
