Combine the first 4 ingredients in a bowl, and stir in 1/4 teaspoon salt. Set aside.
Combine remaining 1/2 teaspoon salt, chili powder, chipotle powder, and shrimp in a large bowl. Heat 1 1/2 teaspoons oil in a large nonstick skillet over medium-high heat. Add shrimp to pan; cook 2 minutes on each side or until shrimp are done. Remove shrimp from pan; keep warm.
Wipe pan clean with a paper towel. Return pan to heat; add 1 teaspoon oil to pan. Place 3 tortillas in pan; cook 30 seconds on each side or until tortillas puff slightly. Repeat procedure with remaining oil and tortillas.
Place 2 tortillas on each of 4 plates, and arrange 4 shrimp on each tortilla. Top shrimp with about 2 tablespoons mango mixture, and serve immediately.