Complex sentence: The texts that had been published in the poetry journals were sent to various academics from a variety of locations, presenting Yasusada as an invented persona that was used by one or more people who intended the keep the origin of the texts secret.
Split into simpler sentences: The texts that had been published in the poetry journals also were sent to various academics. They had been sent from a variety of locations and presented Yasusada as an invented persona that was used by one or more people who intended the keep the origin of the texts secret.