What do you mean Mythic....?
The ranks in Reach go as follows:
Recruit, Private, Corporal, Sergeant, Warrant Officer, Captain, Major, Lt. Colonel, Commander, Colonel, Brigadier, General, Field Marshall, Hero, Legend, Mythic, Noble, Nova, Eclipse, Forerunner, Reclaimer, Inheritor. (Sorry if the order is slightly wrong at the end - This came from the top of my head)
I used to be a Mythic which takes about 4,000,000 cR total to reach before I lost that account, and now that I have a new account, I'm going for it again.