Quote Originally Posted by XenabelleS View Post
Both extremes for Ravana and Bismarck need to be done in order to start the Warring Triad (source, got the quest in my log) so I think you are remembering wrong or else you entered them on someone else's WT run.
That can't be the case. I never cleared Bismark Ex until Stormblood, but did the Triad HM back when it was current.