In a large bowl, combine the shrimp, olive oil, chili powder, cumin, garlic powder, cayenne pepper, salt, and pepper. Toss until the shrimp are well coated in the spice mixture.
Preheat a skillet over medium-high heat. Once hot, add the shrimp in a single layer and cook for about 2-3 minutes on each side or until they are pink and opaque. Remove from heat.
In the same skillet, briefly warm the corn tortillas for about 30 seconds on each side until soft and pliable.
Assemble the tacos by placing a few shrimp on each tortilla. Top with shredded red cabbage and slices of avocado.
Garnish with fresh cilantro and serve immediately with lime wedges on the side.
Notes
Adjust cayenne pepper to taste for desired spiciness.