To prepare the dipping sauce—in a medium bowl combine mayonnaise, sriracha, soy sauce and 1 teaspoon ground black pepper. Chill until ready to use.
In a large bowl combine egg, hot sauce, mustard, 2 teaspoons Creole seasoning, 2 teaspoons black pepper, 2 teaspoons garlic powder, 2 teaspoons onion powder, and a pinch of cayenne. Add the shrimp and mix well to coat.
In a freezer bag combine cornmeal, flour, 2 teaspoons Creole seasoning, and black pepper.
Heat oil in a deep-fryer or a large pot to 350 degrees F. Dip shrimp into the cornflour and coat well. Place shrimp into the hot oil, being sure not to overcrowd the pan (you will need to do this in about 2-3 batches). Cook the shrimp in hot oil for 3-4 minutes or until golden brown and fully cooked. Drain on a plate lined with paper towels.
Squeeze lemon juice over hot shrimp if desired. Serve with the dipping sauce.