If you’re using wooden skewers, soak them in water 15 minutes before grilling so they don't burn.
Blend the soy sauce, brown sugar, ketchup, garlic powder, ground ginger, honey, Worcestershire sauce, ground cayenne and one tablespoon of olive oil in a bowl large enough to hold the chicken cubes.
Reserve ¼ cup of the marinade then set it aside. Add the chicken to the remaining marinade, turning to coat all the pieces then cover with plastic wrap and refrigerate for 30 minutes up to 3 hours.
Cut the peppers, onion and pineapple into about 1” chunks then add them to a bowl. Drizzle with the remaining olive oil then season with salt and pepper to taste.
Remove the chicken from the refrigerator then thread the chicken, vegetables and pineapple onto the skewers, alternating them. Be sure to leave a slight space between each ingredient so the heat can circulate evenly around the chicken.