I've definitely gotten it on my test runs, so I know it's possible. You will know for sure if you are getting all legendary outcomes because there is a special epilogue for achieving that. (and another special epilogue for achieving that and getting jasper's epilogue)
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I just double checked - there's two achievements that will help you know if you are on the right path - there's an achievement with Avalie in week six and an achievement for getting all legendary outcomes in week seven (there aren't any achievements for individual legendary outcomes, just all of them)
hey FearfulSymmetry, sorry to bother you but I've been genuinely struggling for 3 days (I'm not joking) to get Avalie's ending. I've coem to the conclusion that I need to get the Jiyle x Arland legendary ending. If you have some advice for me on how to achieve these ending.
You'll recieve
(+∞ my gratitude) (legendary btw)
(-10000 rivalry with me) (ik, i kinda feel a rage against you because u have gotten the Jiyle ending)