Place the chicken breasts between two pieces of plastic wrap and gently pound them to an even thickness. Season both sides with garlic powder, onion powder, salt, and pepper.
Heat a nonstick grill pan over medium heat and spray with nonstick cooking spray. Cook the chicken for about 5–6 minutes per side, or until the internal temperature reaches 165°F. Let rest for 5 minutes, then slice thinly.
Add the avocado, light ranch, Greek yogurt, lime juice, water, garlic powder, onion powder, salt, and pepper to a blender or food processor. Blend until smooth and creamy. Add a little more water if needed to reach a pourable consistency.
Warm each tortilla for about 10 seconds in the microwave. Place ½ cup lettuce down the center of each tortilla. Top with sliced chicken and about ¼ of the shredded cheese.
Drizzle each wrap with avocado lime ranch dressing.
Fold the sides of the tortilla inward, then roll it tightly from the bottom. Slice each wrap in half and serve.