Preheat the oven to 350 degrees F (175 degrees C). Grease a baking pan.
Place chicken in a large bowl and add Buffalo wing seasoning and ranch dressing mix. Toss to coat.
Combine pepper Jack cheese and Colby-Monterey Jack cheese in a bowl; reserve 1 cup of cheese mixture. Reserve about 1/2 cup Buffalo sauce and pour the rest into a shallow bowl.
Coat both sides of a tortilla with Buffalo sauce and place on a plate. Add desired amount of chicken and cheese mixture. Roll tortilla and place seam-side down in the prepared baking pan. Repeat with remaining tortillas. Cover enchiladas with reserved cheese mixture and drizzle with reserved Buffalo sauce.
Bake in the preheated oven until cheese is melted and tortilla edges are starting to brown, about 20 minutes. Top with blue cheese before serving.
