So I have this thing where Aeon is eventually taken in by the T'au Empire waaaaay later on in his life and he notices that the Tau Fire Caste is composed almost entirely of snipers with no real close quarters skill of any kind, so he decided to head to the council of the Ethereals to request that he train a new caste, a sub-division of the Fire Caste that will be an all-purpose infantry soldier capable of holding their own at close, medium, and long range. This sigil represents the Iron Caste, Aeon's Mobi-vesa sub division to compliment the Fire Caste.

I made this on GTAV's crew Emblem creator btw. >3>