Seigo Yamaguchi can be argued as one of the most influential Aikido teachers of all time. A majority of the Aikido done today can be traced back to his style. One can see his influence all over Hombu Dojo. Some his personal students are Endo Sensei, Tissier Sensei and Yasuno Sensei and all are considered masters today. https://www.youtube.com/watch?v=gSOzgkF2RzI