Cook the rice according to package directions. Once done, fluff with a fork and keep warm.
In a bowl, add diced chicken along with chili powder, cumin, paprika, garlic powder, salt, and pepper. Mix well until all chicken pieces are evenly coated with spices.
Heat olive oil in a large skillet over medium heat. Add the seasoned chicken and spread it out in a single layer. Cook for 3 to 4 minutes without stirring, then flip and continue cooking for another 3 to 4 minutes until fully cooked and lightly browned.
Add the black beans and corn to the skillet. Stir to combine with the chicken and cook for 3 to 4 minutes until heated through.
Add the diced tomatoes and stir gently. Let cook for about 2 minutes until slightly softened and mixed well with the other ingredients.
To assemble, divide the warm rice into serving bowls. Spoon the chicken mixture evenly over the rice. Garnish with chopped cilantro and serve immediately.