In a 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 15-20 minutes.
While the shrimp is marinating, prepare the avocado lime sauce. In a blender or food processor, combine the avocado, sour cream, lime juice, garlic powder, and salt. Blend until smooth and creamy. Adjust seasoning to taste.
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 separate 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 sauce.
Serve immediately and enjoy!