Halo 5: The Guardians Are Coming

So what is a Guardian exactly?

Looking at the first bit of artwork of Halo 5 to come from 343 Industries it's a challenge coming up with who or what 'Guardians' means, but  the symbolism is literally a reflection of Master Chief.

According the to the Halo Wikia - a Guardian is an un-manned, perhaps an un-named object that kills the player. It appears in Halo Combat Evolved, Halo PC, Halo Custom Edition, Halo 2, Halo 2 Vista, Halo 3, Halo 3: ODST, Halo: Reach and Halo 4.

From a programmer's perspective, every entity that can kill you in Halo, i.e., NPC's, an NPC's bullets, your bullets - all have ownership 'tags' attached to them. You see them whenever you die ("_____" was killed by so-and-so) But in those instances where something that doesn't necessarily claim ownership kills you - we get the message: "_____" was killed by the Guardians."

Any clues on the spartan with the glowing blue visor are welcome.  Check out the official Halo Journey Announcement for details from 343's Bonnie Ross.