I am currently 142 spartan level and play H5 daily in Warzone. I unlocked almost every req possible but this set is proving a pain. Any tips, advice or help would be appriciated. Thanks!
Grow your company. Achilles is a team effort. The total amount of stats that go into getting it are massive; even a very active player can only personally contribute a small percentage.
It may help your company to focus on game types that give you more chances at some of the rarer kill types. Focus only on killing Marines in war zone, play swat for headshots/melee kills, etc.
It can only be unlocked by a spartan company and is not available in packs. Broken spirits is getting very close to the helmet if you would like to join.