Legendary Campaign

From the Halo Waypoint forums:

I beat the Campaign on Legendary but didn't unlock the Mark VI armor or commendations.

Complete any Campaign missions for which you are missing the Legendary commendation again. Campaign missions must be completed from beginning to end on the Legendary difficulty using only the "Save and Quit" and "Resume Campaign" features. Once you have all
the Legendary Campaign commendations, you will receive the avatar award.

If that doesn't help, you may need to post your question on the Halo Waypoint forums specifically:

https://forums.halowaypoint.com/

legendary campaign seeker, here.

Definitely gonna have to jump into legendary to try and see if there's a legendary ending to the campaign! I hope there is.

I can help with campaign on legendary for the achievements and armor. And aid with the other campaign achievements.

The single-player campaign is still legendary..ghillies in the mist is still one of my favorite modern CoD missions ever..i think it was the campaign that made it legendary not the multi-player.It's also legendary because this was the last game for many
original CoD fans and the first for the new generation of CoD kids.