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

While the shrimp is marinating, prepare the avocado crema. In a blender or food processor, combine the avocado, sour cream, lime juice, and a pinch of salt. Blend until smooth and creamy. Set aside.

Heat a 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 for about 30 seconds until pliable.

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

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