Kisaburo Osawa Sensei (1910-1991) was a great Aikidoist and one of O Sensei's most loyalist followers.  After O Sensei's passing, he could have run off and started his own organization or martial art and become wildly rich and famous.  Instead he chose to stay at Hombu Dojo and support, Nidai Doshu, Kisshomaru Ueshiba with his burden of carrying on Aikido after O Sensei's death.  Can you imagine just for a moment what that must have been like for not only the students of O Sensei, but for Kisshomaru Ueshiba too at that funeral?  It must have been a heavy burden as everyone expects you to either "be" O Sensei or that you will fail because you are not him.  I am completely sure that he felt a heavy burden and that load was made just a little bit lighter knowing that Osawa Sensei was going to stay and help you. Here is a great video showcasing Osawa Sensei's skill.  Sensei spent time with Osawa Sensei in 1969 in Japan just after O Sensei passed away.  Sensei credited Osawa Sensei as being one of his greatest inspirations and one of the main the reasons he became a priest.  You can also see from this video his enormous influence on Sensei's Aikido too.