Fill a large pot with water and bring it to a rolling boil over medium-high heat. Carefully add fresh corn kernels and let them cook for 5-7 minutes until they are tender yet still crisp. Once cooked, drain the corn in a colander and set it aside to cool completely.

In a large mixing bowl, combine the cooled corn with diced cucumber, halved cherry tomatoes, and finely chopped red onion. Use a large spoon to gently stir the mixture, ensuring that all the ingredients are evenly distributed.

In a separate bowl, whisk together mayonnaise, sour cream, fresh lime juice, chili powder, salt, and pepper until the mixture is smooth and creamy. Adjust the seasoning if desired.

Pour the creamy dressing over the vegetable mixture in the large bowl. Gently toss everything together using a spatula or wooden spoon, ensuring the dressing evenly coats all the vegetables.

To finish, sprinkle crumbled feta cheese and chopped cilantro on top of the salad. Serve the salad chilled to enhance its refreshing qualities.