Heat olive oil in a large skillet over medium heat. Season chicken with chili powder, cumin, garlic powder, salt, and pepper. Cook chicken for 6-7 minutes on each side until fully cooked. Let it rest, then slice into bite-sized pieces.
Cook brown rice using a ratio of 2 cups of water for every 1 cup of rice. Bring water to a boil, add rice, reduce heat to low, cover, and simmer for 45 minutes until tender.
In the same skillet, add corn kernels and cook over medium heat for 3-4 minutes until heated through and slightly charred. Remove from heat.
Prepare lime mayonnaise by mixing mayonnaise, lime juice, and smoked paprika in a small bowl.
Assemble the bowls by dividing cooked brown rice among four bowls. Top with sliced chicken, charred corn, crumbled feta cheese, and avocado slices. Drizzle lime mayonnaise over each bowl and garnish with cilantro. Serve with lime wedges.