Butter a 9 x 13 baking pan. Preheat oven to 350 degrees. Brown meat in skillet, add chili powder, cumin, chiles, refried beans, onions, and mexicorn. Let simmer. Combine soups and enchilada sauce in saucepan, heat over medium heat, stirring until well blended.
Add 1 1/2 cups to the meat mixture, stir until well combined.
Layer 4 tortillas in bottom of pan, overlapping if necessary. Spread meat mixture on top of tortillas, ( 2 to 3 big spoonfuls to cover) Layer 4 more tortillas on top of beef. Top with remaining tortillas then the rest of the soup and enchilada sauce, then add cheese. Bake uncovered 30 minutes until bubbly and light brown. Garnish with black olives and chopped green onions.