In a large bowl, mix together the cumin, garlic powder, chili powder, 1 teaspoon salt, red pepper flakes (if using), and black pepper. Pat the shrimp dry and add to the bowl. Toss to coat thoroughly so there are no spices left behind!
In a large non-stick skillet over medium heat, warm the olive oil. Add the shrimp to the skillet and cook for about 2-3 minutes per side, or until cooked through.
While the shrimp cooks, make the yogurt by mixing all ingredients in a small bowl. If your yogurt is thick, thin it out with some water to your desired consistency.
Add the cabbage to the medium bowl along with 2 tablespoons of the yogurt dressing and remaining ¼ teaspoon salt and toss to coat.
Warm the tortillas (I like to do this over an open flame to get some char). Top with avocado and mash it up. Add cabbage, shrimp, and mango slices. Drizzle with yogurt dressing and a squeeze of lime.