When describing something that is covered in soot, there are several synonyms that can be used instead of "most soot-covered." Some of these synonyms include "charred," "smudged," "grime-coated," and "ashen." Other options include "sooty," "carbonized," "blackened," and "smoky." Each of these words conveys a similar meaning to "most soot-covered" and can be used in different contexts depending on what is being described. For example, "charred" may be used to describe wood that has been burned, while "sooty" may be used to describe a chimney covered in soot. Regardless of the context, these synonyms provide a more versatile and varied way of describing something covered in soot.