Place shredded chicken in a medium bowl and mix with hot sauce.
In a separate medium bowl, mix together cream cheese, blue cheese, and celery in a separate bowl.
Butter one side of each of your slices of bread. Flip bread over and generously slather cream cheese/blue cheese mixture on top of each slice. On two of the bread slices, divide buffalo chicken and layer a few slices of cheese on top of it.
Heat a griddle or frying pan to medium heat. Place slices of bread with buffalo chicken on griddle butter-side-down and top with remaining bread slices, butter-side-up.
Cook for a couple minutes on each side, until bread gets nice and toasty and cheese gets melty.