So I was trying to obtain the helioskrill armor in halo 5, I completed all of the campaigns on legendary difficulty, either on co op or solo.
I completed the entire campaign of halo 2 on legendary solo, however I was not awarded the achievements or avatar pictures on the mcc. My game says I completed the missions on the legendary (15/15) but when I look on waypoint it says I only completed 3 of the missions.