In 2001 Dan met Seishiro Endo Shihan (8th Dan) while training at the Aikikai Hombu Dojo in Tokyo. A close student of the late Seigo Yamaguchi Shihan (1924-1996), Endo sensei's style of aikido is considered to be of the "Yamaguchi-lineage". Finding an immediate connection, Dan began following Endo sensei at various seminars in Europe, Japan and later in America. To further explore this unique path of aikido, Dan began (and continues today) to invite Endo sensei's senior students to the US for seminars and workshops to spread his personal message of aikido.
In 2004 Dan sensei and Duff Swan sensei left the Shindai Aikikai dojo (and the ASU) to form the Central Florida Aikikai, an independent aikido group dedicated to following Endo sensei and his teaching of aikido.
In 2010, the CFA came under the direction of Jan Nevelius Shihan (6th Dan Aikikai) upon the recommendation of Endo Shihan. In 2014 Dan tested for and received his yondan (4th Dan) directly from Jan sensei.
In January of 2020, upon the recommendation of Endo Sensei, Dan was promoted to godan (5th Dan) by the Aikikai Hombu Dojo.
After re-dedicating himself to a new style of aikido for almost ten years, Duff's patience and efforts were rewarded as he tested with Endo sensei in 2012 for his shodan, passing with praises from all in attendance. In 2016, Duff tested and passed his nidan promotion with Jan Nevelius Shihan. He successfully tested again in 2019 and was awarded his sandan.