Preheat your oven to 375°F (190°C).
In a large bowl, combine the shredded chicken, 3/4 cup of buffalo sauce, cooked rice, 1/2 cup of cheddar cheese, ranch dressing, olive oil, garlic powder, onion powder, salt, and black pepper.
Mix the ingredients well until everything is evenly coated with the buffalo sauce mixture.
Arrange the bell pepper halves in a baking dish and fill each one generously with the buffalo chicken mixture.
Pour the remaining 1/4 cup of buffalo sauce over the stuffed peppers and sprinkle with the remaining 1/2 cup of cheddar cheese.
Cover the baking dish with foil and bake in the preheated oven for 25 minutes.
Remove the foil and bake for an additional 10 minutes, or until the peppers are tender and the cheese is melted and bubbly.
Remove from the oven and let cool for a few minutes before serving.