In a mixing bowl, combine the olive oil, chili powder, paprika, cumin, salt, and black pepper. Add the shrimp and toss to coat evenly. Let it marinate for about 10 minutes.
In another bowl, combine the diced mango, red onion, jalapeño, cilantro, and lime juice. Mix well and set aside to prepare the mango salsa.
Heat a large skillet over medium-high heat. Once hot, add the marinated shrimp and cook for about 2-3 minutes on each side, or until they turn pink and opaque. Remove from heat.
Warm the corn tortillas in the same skillet for about 30 seconds on each side, or until pliable.
To assemble the tacos, place a few shrimp on each tortilla, top with the fresh mango salsa, and add optional avocado slices and lime wedges for garnish.
Serve the tacos immediately and enjoy!