For the Marinade: Mix together the juices, chile powders, paprika, cayenne, cilantro and oil. Add the chicken thighs and let marinate for 2 hours in the refrigerator. Preheat grill pan. Remove chicken from marinade and thread each chicken half onto 2 skewers so that the meat stays flat on the grill. Season with salt and pepper and grill for 4 minutes on each side or until cooked through. Remove chicken from the grill pan and brush liberally with the tangerine glaze, serve on a platter, serve with the relish and garnish with chives. Serve with flour tortillas.
For the Glaze: Heat the olive oil in a medium saucepan over medium-heat. Add the shallots and cascabel powder and cook until soft. Raise the heat to high, add the vinegar, sugar and tangerine juice and reduce to a syrup. Season with lemon juice and honey to taste. Add the olive oil and season with salt and pepper. Let cool.
For the Tangerine-Pomegranate Relish: Combine all relish ingredients well.