Heat olive oil in a large skillet over medium-high heat.
Add corn and season with smoked paprika, salt, and pepper. Sauté for 5–7 minutes, stirring occasionally, until lightly charred.
In a small bowl, whisk together sour cream, harissa paste, lime juice, and water until smooth.
Transfer cooked corn to a large mixing bowl. Let cool for a few minutes.
Add avocado, cilantro, scallions, and feta cheese to the corn and gently toss to combine.
Drizzle harissa ranch over the salad and mix until evenly coated. Serve immediately or chill before serving.