Duane's creation of the Rihannsu was generally well received by fans, with some going so far as to lobby Paramount to accept them as canonical.
At least three different explanations are given in Trek novels--The Price of the Phoenix, Rihannsu#1: My Enemy, My Ally and Vulcan's Heart--(in the early days of Trek writing, many novels tended to contradict each other, and so the commander has had many different names and fates).