plz help

I Played every halo game on Legendary and didnt got the helio armor why???

You missed requiem for one.

what do you mean

Looks like you haven’t unlocked the Legend achievement yet. I can see you have played all the levels, but the Halo 4 level requiem isn’t showing legendary completion. if you play that level again, either cop-op or solo, you should unlock the achievement and get Helioskrill

Also in future please try and title your topic more appropriately