In a medium shallow bowl, whisk together olive oil, lime juice, paprika, chili powder, cumin, and cayenne.
Add cod, tossing until evenly coated. Let marinate 15 minutes.
Meanwhile, make slaw: In a large bowl, whisk together mayonnaise, lime juice, cilantro, and honey. Stir in cabbage, corn, and jalapeño. Season with salt and pepper.
In a large nonstick skillet over medium-high heat, heat vegetable oil. Remove cod from marinade and season both sides of each filet with salt and pepper. Add fish flesh side-down. Cook until opaque and cooked through, 3 to 5 minutes per side. Let rest 5 minutes before flaking with a fork.
Assemble tacos: Serve fish over grilled tortillas with corn slaw and avocado. Squeeze lime juice on top and garnish with sour cream.