Heat your grill or a grill pan to medium-high heat.
In a mixing bowl, combine the shrimp with olive oil, onion powder, smoked paprika, sea salt, and black pepper, ensuring each shrimp is evenly coated.
Once the grill is hot, skewer the shrimp (if using wooden skewers, soak them in water for 30 minutes first).
Grill the shrimp for about 2-3 minutes on each side, or until they turn pink and are fully cooked. Remove them from the grill and set aside to rest.
In another bowl, mix together the corn, diced avocado, grape tomatoes, red bell pepper, parsley, and lime juice. Stir gently to combine all the ingredients.
In a small bowl, whisk together the Greek yogurt, lime zest, and chili powder until smooth and creamy.
To build your fiesta bowls, start by placing a generous portion of cooked quinoa in each bowl. Layer the grilled shrimp on top, followed by a hearty scoop of the avocado-corn relish. Finish with a drizzle of the zesty yogurt sauce.
Serve right away and savor the vibrant flavors!