In a small bowl, mix the paprika, garlic powder, oregano, cayenne, salt, and black pepper. In another small bowl, stir together the sour cream, lime zest, lime juice, hot sauce, and salt. Taste and adjust - you want it tangy and just a little spicy. Set both aside.

Pat the tilapia completely dry with paper towels - this is crucial for getting a good crust. Rub the olive oil all over both sides of each fillet, then press the spice mixture evenly onto both sides. The fish should look almost crusted with spices; don't be shy.

Heat a large cast-iron skillet over medium-high heat until very hot, about 3 minutes. Add a thin film of oil and let it shimmer. Carefully lay in the fillets - don't crowd the pan; work in batches if needed. Cook without moving for 3 to 4 minutes until the underside is deeply browned and almost charred in spots. Flip gently and cook 2 to 3 minutes more until the fish flakes easily. Transfer to a plate and break into rough chunks.

While the fish rests, warm your tortillas directly over a gas flame for 15 seconds per side, or in a dry skillet, until soft and slightly charred. Wrap in a clean towel to keep warm.

Spread a spoonful of lime crema on each warm tortilla. Top with a generous handful of shredded cabbage, a few chunks of blackened tilapia, a drizzle more of crema, and a scattering of cilantro. Serve immediately with lime wedges on the side for squeezing.