In a large skillet, heat the olive oil over medium heat. Add the diced chicken and season with chili powder, garlic powder, cumin, salt, and pepper. Cook for about 6-8 minutes, or until the chicken is cooked through and no longer pink. Remove from heat and set aside.
In the same skillet, add the corn and cook for 2-3 minutes until heated through.
In a small bowl, mix together the mayonnaise, sour cream, and lime juice until well combined.
To assemble the bowls, start with a base of cooked rice. Top with the cooked chicken, corn, and drizzle the mayo mixture over the top.
Sprinkle crumbled feta cheese and chopped cilantro over each bowl. Add sliced avocado and serve with lime wedges on the side.