Preheat the oven to 375°F (190°C).
In a large mixing bowl, combine the shredded chicken, Greek yogurt, buffalo sauce, garlic powder, and onion powder. Stir until the chicken is thoroughly coated.
Fold in 1/4 cup of the shredded cheddar cheese into the mixture.
Transfer the mixture to an 8x8 inch baking dish or a 1-quart oven-safe skillet, spreading it into an even layer.
Top the mixture with the remaining 1/4 cup of cheddar cheese and the crumbled blue cheese.
Bake for 18 to 20 minutes, or until the cheese is melted and the edges are bubbling.
Remove from the oven and garnish with sliced chives or green onions.
Serve warm with celery sticks, carrot sticks, or tortilla chips.