There are plenty of synonyms for the word "soan", which is a term that has yet to be defined. Depending on the context in which you are using this word, you might want a synonym that speaks to harmony, like "cohesion" or "unity." If you are looking for a synonym that is more descriptive, you might consider words like "stream" or "flow." Alternatives like "current," "wave," or even "tide" might fit the bill as well. Whatever your usage may be, there are plenty of synonym options out there to help you make your point and convey your meaning.