mystic trophy wont unlock

[JU_X_TWO]

Ive got friends who were already doing paragon lvls when I started playing and they told me adventure mode is alot faster to lvl than the campaign. I was almost done with act 2 when they told me I could just join on them at the end to take out the last boss so I could unlock adventure mode and I did. I have since went and finished the campaign that I skipped but the mystic trophy didnt unlock.

So have I just screwed myself on this trophy or what? After we beat the final boss I did notice that the mystic was already there to enchant but the trophy never popped. And ive went through act 5 where I saved her but it didnt pop there either.