Thread:FixSRwiki/@comment-79.180.68.238-20180217214029/@comment-26544499-20180218114116

To the best of my awareness, Mamamune acts as I've said in the walkthrough. He'll join if Rance defeats him in a duel (and no other way). So as you've said, neither vassaling nor having Kenshin defeat him will be sufficinet.