In a bowl, toss the shrimp with olive oil, chili powder, garlic powder, salt, and pepper.
Heat a grill pan or outdoor grill over medium-high heat. Grill the shrimp for about 2-3 minutes per side, until cooked through.
If using fresh or frozen corn, sauté in a pan with a little olive oil until slightly charred and cooked through, about 5 minutes. If using canned corn, just drain and rinse.
Mix the mayo with 1 teaspoon of lime juice and 1 teaspoon of hot sauce. Mix until combined.
Divide the cooked rice into bowls. Top with grilled shrimp, corn, and avocado.
Pour some of the fresh lime juice over the bowl, garnish with chopped cilantro, and drizzle on the dressing.