Preheat oven to 350 degrees F. In large saucepan cook onion in oil until translucent or 5 min. Stir in chili powder, garlic powder, and cumin. Add cream cheese, and cook over low heat. Break cheese into chunks until melted. Add chicken and salsa. Stir over medium heat 2 to 3 minutes until hot. Remove from heat. Stir 1 1/4 cups of cheddar and black olives. Wrap tortillas in stack of 8-inch foil and heat in oven until pliable.
Spread 1/4 cup enchilada sauce over bottom of two 11x7 baking dishes. Spoon 1/3 cup of chicken mixture slightly below center of each tortilla. Roll up from bottom seam side down in dish. Pour remaining sauce on top and sprinkle with remaining cheddar cheese.