In a medium bowl, add oil, lime zest, lime juice, garlic, chipotle chili powder, red pepper flakes, black pepper, salt, and Mexican oregano. Whisk together to combine.
Add shrimp and toss together to coat. Set aside to marinate while you make the slaw.
Heat oil in a medium nonstick skillet over medium-high heat. Add corn and cook for 8 minutes, stirring occasionally, until corn begins to brown. Remove from heat and transfer to a medium bowl.
To the same bowl, add the red cabbage, jalapeno, cotija cheese, mayonnaise, cilantro, sour cream, lime juice, and chili powder. Toss together to combine, taste, and season with salt to taste. Set aside until ready to serve.
Heat a large nonstick skillet over medium-high heat. Add the shrimp and sauté for 4-6 minutes, flipping halfway through, until the shrimp are cooked through.
Assemble the tacos by placing a bit of the slaw in warm tortillas, top with a few shrimp, and garnish with a bit of chopped cilantro and cotija cheese.
Notes
Don't have chipotle chili powder? You could use 1 or 2 canned chipotle chiles in adobo sauce instead. If you don't have that either, you can use regular chili powder.
Don't have Mexican oregano? The Mexican oregano adds a very distinct flavor to the shrimp (learn more about Mexican oregano), so I recommend using it if you can. However, if you don't have any, you can use regular oregano instead.