In a medium bowl, combine the olive oil, chili powder, cumin, garlic powder, onion powder, salt, and pepper. Add the chicken strips and toss to coat. Let marinate for 10 minutes.
Preheat an outdoor grill to high heat. Grill the chicken strips for 4-5 minutes per side, or until cooked through.
Meanwhile, warm the tortillas in a dry skillet over medium-high heat for 1-2 minutes per side, or until lightly browned and pliable.
In a small bowl, combine the diced avocado, cilantro, and lime juice. Mash until smooth.
To assemble the tacos, fill each tortilla with chicken strips and top with the avocado-cilantro sauce. Enjoy!