01 - In a large bowl, combine shredded chicken, buffalo wing sauce, mozzarella, blue cheese if using, celery, green onions, garlic powder, and black pepper. Mix thoroughly until the ingredients are evenly distributed.
02 - Place an egg roll wrapper on a clean surface in a diamond orientation. Spoon 2 to 3 tablespoons of filling onto the center of the wrapper. Fold the bottom corner over the filling, tuck in the sides, and roll tightly. Brush the top corner with the beaten egg to seal the edge.
03 - Continue assembling the remaining egg rolls with the rest of the filling and wrappers, making sure each is sealed well.
04 - Pour vegetable oil into a deep-frying pot to a depth of approximately 2 inches. Heat oil to 350°F (175°F) using a thermometer for accuracy.
05 - Fry egg rolls in batches, turning as needed, until golden brown and crispy, about 3 to 4 minutes per batch. Remove with tongs and transfer to paper towels to drain excess oil.
06 - Plate egg rolls while warm and present with ranch or blue cheese dressing for dipping.