The phrase "into/out of thin air" is often used to describe something that appears or disappears suddenly and with no clear explanation. Some synonyms for these phrases include "out of nowhere," "seemingly from nowhere," "like magic," "mysteriously," "suddenly and inexplicably," and "unpredictably." These phrases are often used to evoke a sense of surprise, wonder, or intrigue, and can be used in a variety of contexts, such as in describing unexpected events or sudden changes in circumstances. Whether used in conversation, writing, or storytelling, these synonyms help to add depth and interest to language, and give readers and listeners a sense of the unexpected.