The Didact was such a great character and Endurance really seemed to have the potential for a major role when I was reading Silentium, however now both are composed. Endurance it’s a confirmed Knight (though, we never knew what happened to her after that, neither if she was a special variant of Knight nor if she had a plan to not end completely mindless) Didact in the other hand, well, we only know that he was composed and that he is definitely not Warden, a glimpse of hope that I have on at least one of them was the Boltshot entry on the canon fodder; it seemed to imply that someone provided Endurance’s Boltshots blueprints for ONI (and I’d assume the rest of legendary Forerunner weapon variants come from the same source). I think any of them could be that link.