Apart from different varieties of peppers, such as black, white, and cayenne pepper, cajun spice contains other spices and herbs. They can include onion powder, garlic powder, salt, thyme, rosemary, and oregano.
It's why cajun spice isn't just spicy. It also has a distinct earthy, smoky flavor. While this flavor profile is good news, you have to make sure you tweak the measurement of the other spices and herbs used in your recipe.
Consider combining tomato juice and hot sauce if you want a spicier and hotter blend. Simply follow the same ratios as above to make the blend and replace paprika in your recipes.