While the chicken is cooking, mix in a bowl the chicken broth, the chili powder, paprika, cumin, onion powder, garlic powder, and cayenne pepper. Whisk until thoroughly mixed.
After the chicken is cooked, remove from the grill and put them in a stand mixer with a paddle attachment. Start off slowly then bring to full speed. This will shred the chicken perfectly for tacos (or barbecue chicken sandwiches). At first my mixer thumped a lot and tried to walk off the counter, so keep an eye on it.
Add the liquid to the shredded chicken until it is moist (not sopping). The amount required will vary based on how closely you watched the chicken on the grill. Too long = dry = add more liquid.
Warm the tortillas in a frying pan.
Assemble the taco with chicken, cheese, tomatoes, lettuce, guac, sour cream, a squeeze of lime, some salsa and whatever taco ingredients float your taco boat.