I played all the Halo games in Legendary for get the Helioskrill armor, I get the Legend (TMCC) trophy, but when I see in Halo 5 I dont have it, please fix it and help me!.
It won’t necessarily unlock right after you unlock the achievement. All your game data needs to sync up first. Go ahead and check Halo 5 again to see if it’s there. If not, change a customization option in MCC, save it, change it back (assuming you liked your old set up), and then check Halo 5 again.
I agree with the post above, but I noticed something reviewing your profile.
While Helioskrill does require the Legend achievement (which you have), for some reason it does not show you have beat the first three missions of Halo: CE. This should not matter as it checks for the achievement, but if for some reason it doesn’t give you the armor you may want to try beating those again just to be sure.
Delete the game, Redownload it. It worked for me, hope this helps.
Please see the pinned thread about Helioskrill for help on this, thanks