If we are referring to academic vocabulary, we mean to say the words or group of words that are used in the academic dialogue. These words are not common and are not frequently encountered in daily conversations. We can change the word awful to dreadful.
The best revision of this phrase using the academic vocabulary would be "The protagonist of" Mericans, "Micaela, expresses that her grandmother is awful."
Explanation:
Unlike many may think, academic language should not be boring, confusing, or obscure. On the contrary: the clearer the meaning of the text, the better for the reader. Thus, the academic language must pass a message in a formal and educated way, passing all the necessary information with the correct use of grammar and spelling, as it was done in: "The protagonist of" Mericans, "Micaela, expresses that her grandmother is awful."