In a medium bowl, combine your finely chopped shrimp with the chipotle powder, cumin, onion powder, avocado oil, salt, and pepper. Toss to coat evenly and let it sit for 10 minutes while you prep the rest of your ingredients and your crema.
In a small bowl, mix together the sour cream, mayo, lime zest, lime juice, chipotle powder, garlic powder, and salt. Add a tiny splash of water and whisk until smooth and drizzle-ready.
Heat a large skillet over medium-high heat. Add the avocado oil and butter. Once melted, add the corn kernels and a pinch of salt. Spread them out into an even layer and let them cook, stirring only occasionally, until they are beautifully charred and lightly golden.
Add the chipotle powder, cumin, and onion powder to the charred corn and stir for about 30 seconds to let the spices bloom in the heat. Immediately add your marinated shrimp to the skillet. Cook, stirring frequently, just until the shrimp turns pink and opaque (this will be fast, just 2 minutes or so.)
Turn off the heat completely. Squeeze the fresh lime juice over the shrimp and corn mixture, tossing well to combine.
Wrap your corn tortillas by wrapping them in a damp paper towel and microwaving for 30 seconds, until soft and pliable. Build your tacos: lay down a base of crema, add the red onion and cilantro, pile on the warm elote shrimp mixture, drizzle with more crema, and finish with cotija cheese, a dusting of extra chipotle powder, and a squeeze of fresh lime. Serve immediately!