Preheat your oven to 400°F and shred your chicken.
In a large mixing bowl, combine the cream of chicken soup, buttermilk ranch dressing, sour cream, buffalo hot sauce, onion powder, garlic powder, celery salt, and black pepper. Whisk everything until smooth and fully combined.
Fold in the shredded rotisserie chicken, ensuring it's evenly coated with the creamy buffalo sauce mixture.
Pour the chicken mixture into the prepared baking dish, spreading it out into an even layer.
Sprinkle the shredded cheddar cheese over the top of the entire casserole.
Arrange the frozen tater tots on top in a single layer, covering the entire dish.
Bake in the preheated oven for 40 minutes, then broil on low, on the middle rack, until the cheese is bubbly and the tater tots are golden and crispy.
Remove the casserole from the oven and let it cool for a few minutes before serving.
Dish up and enjoy that creamy, cheesy, spicy goodness!