In a medium bowl, combine the shrimp, olive oil, chili powder, cumin, garlic powder, paprika, salt, and pepper. Toss until the shrimp are evenly coated. Let marinate for 15 minutes.

While the shrimp are marinating, prepare the avocado lime crema. In a blender or food processor, combine the avocado, sour cream, lime juice, garlic powder, and salt. Blend until smooth and creamy. Adjust seasoning if needed, then set aside.

Heat a large skillet over medium-high heat. Add the marinated shrimp and cook for 2-3 minutes on each side, or until they are pink and opaque. Remove from heat.

Warm the tortillas in a dry skillet or microwave until pliable.

To assemble the tacos, place a few shrimp on each tortilla, top with shredded cabbage, diced tomatoes, and fresh cilantro. Drizzle with avocado lime crema.

Serve with lime wedges on the side for squeezing over the tacos.