More mondo is a phrase that is often used to describe something that is extremely cool or impressive. When trying to come up with antonyms for this phrase, you could consider words that describe things that are the opposite of cool or impressive. Some potential antonyms for more mondo might include phrases like "less impressive," "not very cool," or "rather average." Another way to look at it might be to think about things that are the opposite of big or grand, since the word "mondo" has connotations of size and scope. Some antonyms in this context might include words like "small," "diminutive," or "unimpressive.