Combine flour, paprika, black pepper, and salt and whisk to combine. Transfer half of mixture to a large bowl and set aside. Add beer and egg to remaining mixture and whisk until a smooth batter is formed. Batter should have the consistency of thick paint (add up to ½ cup more beer as necessary until proper consistency is reached). Set aside.

Combine mayonnaise and hot sauce in a medium bowl and whisk until homogenous. Set aside.

Heat oil in a deep fryer, Dutch oven, or large wok to 350°F (175°C). Transfer fish pieces to bowl with batter and turn to coat thoroughly. Working one piece at a time, lift fish, let excess batter drip off, then transfer to bowl with remaining flour mixture. Toss to coat thoroughly. Lift carefully with tongs or dry fingers and slowly lower into hot oil. Repeat with remaining fish.

Fry, turning occasionally, until golden brown on all sides, about 3 minutes total. Transfer to a paper towel-lined plate and season with salt.

Divide tortillas into 8 double stacks. Top each with shredded cabbage, 1 piece of fish, pickled red onions, chile mayo, and cilantro. Serve with lime wedges.