In a large bowl, whisk together buffalo sauce, ranch dressing, olive oil, garlic powder, onion powder, salt, and pepper. Add the chicken pieces and toss to coat. Cover and refrigerate for at least 30 minutes (or up to 2 hours for more flavor).
Preheat your grill to medium-high heat. If using wooden skewers, soak them in water for at least 30 minutes to prevent burning.
Thread the marinated chicken pieces onto the skewers, dividing evenly.
Place the skewers on the hot grill. Cook for about 4–6 minutes per side, turning occasionally, until the chicken is fully cooked and has a nice char.
Remove from the grill and let rest for a few minutes. Garnish with chopped parsley and serve with extra ranch dressing or blue cheese dip if desired.