In the February update for halo 5 there are 2 new variants of helioskrill armour.
because this armour is regarded as an achievement for beating mcc on legendary , it should be the same for halo 5.
If you complete the campaign on legendary you get one variant.
and the other could be ibtained through a spartan company , similar to Achilles.
Just my opinion so that the people who worked for it aren’t completely made fun of