The fact that it’s taken the Halo franchise so long to heavily take inspiration from ancient armor is still crazy to me, luckily that route’s been taken lately and I love it, I really hope these creations keep coming, I’d love a Corinthian-inspired helmet (the Achilles is the closest thing we have to that but it’s still pretty far off), a Roman galea one, Aztec or Maya over the top ornaments or motifs (e.g. the Xicalcoliuhqui) for visors, certain pieces or even the entire armor (the Helioskrill could be great for that), Vitruvian scrolls, triskelions and meanders flowing down from a Spartan’s armor, a toned-down knight’s frog-mouth helm (Stechhelm [“jousting helmet”]), a lorica squamata
(“scaly coat of mail/breastplate”), a Viking Age-inspired helmet (check the surviving piece of the Gjermundbu), etc.
To speak a little bit about this armor, it’s basically a futuristic Ō-yoroi (Japanese for ”great armor”). The major components found in Halo’s Yoroi are the dō (“cuirass”), the kabuto (“helmet”) and the kote (“armoured sleeves”). The ō-yoroi combines plate and scales (kozane) laced together (lamellar), the helmet’s “flaps” are called shikoro, they’re a suspended neck guard composed of multiple overlapping scales.
The coating’s color also makes sense for its look: The Ō-yoroi’s kozane are first laced together and then covered with lacquer, which enhances resistance to corrosion.
Last but not least, the maedate (“plume, crest”) is pretty spot-on compared to the original ones and the sword we see in the Spartan’s hip is a tantō (“short sword”), a tantō is a Nihonto (i.e. a traditionally-made Japanese bladed weapon) worn by the samurai class of feudal Japan, it was traditionally used for committing seppuku.
P.s.: 343i being inspired by ancient stuff and applying it is cultural appreciation, not cultural appropriation, hopefully people get that.