In a large bowl, combine the green cabbage, purple cabbage, chopped cilantro, mayonnaise, honey, lime juice, salt, and pepper. Toss well until all ingredients are evenly coated. Cover and refrigerate for at least 15 minutes to let the flavors meld.

In a separate bowl, whisk together the sour cream, mayonnaise, lime juice, garlic powder, cumin, and salt until smooth and creamy. Set aside for serving.

In a mixing bowl, combine the flour, cornstarch, paprika, garlic powder, salt, and black pepper. Gradually add the cold sparkling water and whisk until smooth; the batter should be light and airy.

Heat vegetable oil in a deep pan over medium-high heat. Once hot, dip the fish pieces into the batter, coating fully, and carefully lower them into the oil. Fry until golden brown and crispy, about 3-4 minutes per side. Remove and drain on paper towels to absorb excess oil.

Warm the tortillas in a skillet or microwave. Start by placing a generous scoop of slaw onto each tortilla, followed by pieces of crispy fish. Drizzle over the prepared sauce and add any optional toppings you desire.

Sprinkle with additional chopped cilantro and serve with lime wedges on the side for squeezing over the top.