In a large pot of boiling salted water, cook the elbow macaroni according to package instructions until al dente. Drain and rinse under cold water to cool.
In a small bowl, whisk together the mayonnaise, Greek yogurt, lime juice, chili powder, salt, and pepper until smooth.
In a large mixing bowl, combine the cooled macaroni, cherry tomatoes, black beans, corn, red onion, and cilantro.
Pour the dressing over the macaroni mixture and stir gently until all ingredients are well-coated.
Carefully mix in the diced avocado and shredded cheddar cheese, being cautious not to mash the avocado.
Cover the salad and refrigerate for at least 30 minutes to allow flavors to meld together.
Give the salad a gentle toss before serving to redistribute the dressing and ingredients.