In a medium bowl, place the tuna, shrimp, paprika, onion powder, garlic powder, lime juice, bread crumbs, cumin, red pepper flakes, salt and pepper and mix well. Add the beaten eggs and mix to combine.
Form the mixture into round cakes. In a large saute pan over medium-high heat, fry the cakes in the oil, turning once, until lightly browned, about 3 minutes per side.
To make the avocado sauce: Place all the ingredients in a blender a blend until smooth. Transfer to a serving bowl. Season to taste.