halo 3 armors..what about the rest?

halo 3 was the first time we got to really customize our armor. we could be more than just blue/orange or an elite. we picked a nice armor and grew attached to it.
and so alot of our possible favorites lived on to halo reach (not hayabusa,scout, or rogue) and halo 4 and 5 (not hayabusa, rogue, CQB)
i was thinking since odst ,recon, operator , scout and eod (why eod?) have lived on since halo 3 why not
rogue , hayabusa , and CQB (CQB is favorite)…?

so i had an idea for a more challenging way for them to not just be unlocked by leveling.

Hayabusa:
unlock achievement
Body:–“yes sensei: on legendary: kill 3 of the 4 sword elites on ??? mission with a sword.”
–“slice to meet you:in matchmaking, Earn an over kill with a sword”
–obtain:8 skulls
Helmet:
–‘in a matchmaking game, earn at least 50 kills with a sword’
–‘find the helmet on legendary,carry it to the end of :mission: afterwards it triggers a sword only firefight’
–obtain all skulls
(requires body unlock)
Rogue:
achievement:
Body:–“goin’ rouge: on legendary: find master chiefs cloak”(triggers a 3 wave fight)
–“speak no evil:on legendary: sneak up on a couple of grunts, wait for them to say something and (only) meele the one that makes fun of you”
Helmet:
–‘earn a rogue metal, 3 betrayals multi-player.(without dying)’
–“he’s gone rampant!”–on (blank) mission endure 12 waves of marines. betray a few to start a firefight.
(requires body unlock)

CQB:
achievement:
Body:–“see thru me?”: on legendary: kill every enemy with close quarters"
(on a part of a mission where you cant back track…could require camo)
–“earn a bull-true,show stopper, dream crusher, open season, and slice’n’dice”
Helmet:
–find and claim on legendary,(spawns 6 enemy sword elites)
–‘in a multiplayer game get atleast 30 close quarters kills’
–get a total of 2,000 close quarters kills with a minimum of 200 in each category.
(meele-sword-hammer-shotgun-and assassinations)
(requires body unlock)

So unlock armor through achievements

I would like a more of a challenge for hayabusa so less people have it. Something like getting a perfection with only melee or the sword/ complete slaso with no shots fired(or 5 or less shots if they are required)

We also need one of these classics to be the new recon, so almost impossible to get.

got an idea for a couple extra rogue ones?

what kind of challenges would be more suiting for these classic armors?