In a small bowl, whisk together the Greek yogurt, half of the lime juice, and a pinch of sea salt to create a zesty crema.
In a separate medium bowl, toss the shredded cabbage with the remaining lime juice and chopped fresh cilantro.
Pat the shrimp dry with a paper towel and season evenly with chili powder, ground cumin, garlic powder, and sea salt.
Heat the olive oil in a large skillet over medium-high heat until shimmering.
Add the shrimp to the skillet in a single layer and sear for 2-3 minutes per side until pink, opaque, and slightly charred.
Warm the corn tortillas in a dry pan over medium heat for 30 seconds per side until pliable and toasted.
Assemble the tacos by layering the cabbage slaw, chili-lime shrimp, and sliced avocado into the warm tortillas, then finish with a drizzle of the yogurt crema.