In a medium bowl, whisk together dark chili powder, smoked paprika, ground cumin, red pepper flakes, kosher salt, lime juice, and avocado oil to form a marinade. Add the shrimp and coat well. Cover and refrigerate for up to 30 minutes.

While the shrimp marinates, blend the avocado, cilantro, jalapeño, garlic, lime juice, Greek yogurt, avocado oil, and a pinch of salt in a food processor until smooth. Adjust thickness with water if necessary.

Thinly slice the cabbage and toss with some avocado crema to lightly coat, creating a refreshing slaw.

Heat a grill pan or skillet over medium-high heat. Cook the marinated shrimp for about 4 to 6 minutes, flipping halfway through until they turn opaque.

Warm the tortillas in a skillet or microwave. Assemble the tacos by placing shrimp, a scoop of cabbage slaw, and remaining avocado crema on each tortilla. Garnish with fresh cilantro and lime wedges.