In a small bowl, combine chili powder, cumin, garlic powder, paprika, and salt to make the spice blend.
Heat olive oil in a large skillet over medium-high heat; add diced chicken and sprinkle with spice blend.
Cook chicken for 8-10 minutes, stirring occasionally, until fully cooked through and slightly charred on edges.
While chicken cooks, warm black beans and corn together in a small saucepan or microwave.
To assemble bowls, divide rice among four bowls and top each with seasoned chicken, black beans, corn, shredded cheese, salsa, diced avocado, and sour cream.
Garnish with fresh cilantro and serve with lime wedges for squeezing over the top.