And no, I am not implying they all have mjolnir armour, this was just what I saw as the best way to get at least an idea for what they'll look like, but yes, I am implying they all have helmets.
Name: Donovan k. Torrent
Nickname: Doktor/The Doktor
Look:"And here I'd like to quote an old earth video game I used to play. Practically a relic in age and quality, yet still thriving in community. 'It's time to practice medicine.'"
- 'Doktor' Donovan K. Torrent to a captured insurrectionist soldier he was tasked with keeping alive while being transported to viable location for proper interrogation
Said interrogation was later deemed unnecessary after 'Doktor' managed to 'convince' the soldier to willingly give up all of the wanted answers and then some.
Weapons: Type-53 plasma caster
I suppose you could also consider his medical kit, a rather large bag with a red cross crudely stitched on it, as such. It does have a rather disturbing amount of scalpels in it... and is that a bone-saw in there?
I-either way, it has more than enough in it to accommodate surgery for a full squadron and maybe even then some if the injuries requiring surgery weren't too supply costly.
Of course it was never said said accommodation would be a comfortable one
Bio: Donovan, or Doktor was trained to be, and is one of the best in the field of in, and out of combat aligned medical practices, and torture/'information gathering' skills you'll meet. Though the second was less a purposely taught skill, than a... welcomed 'discovery'.
He is also most assuredly has at least some form of mental problem/condition. His tendency towards making rather... dark, and less than comedic 'jokes' certainly doesn't help in convincing otherwise.
'Doktor' took the sudden declaration of peace rather... well. Oddly too well at that. While certainly not active in attempting to befriend their alien foes suddenly turned comrade, he's far from hostile towards them... and just as far friendly... though that's not that unusual, he's always seemed to treat everybody rather the same... almost as if he saw them all through the same film of neutrality.
'Doktor' (as he's become nicknamed) was assigned to the same team as 'Bouncer', and 'Quotes', the only surviving members of their squad.
Name: Daniel Ruiz
Nickname: Quotes or TOS/Toss
Look:"Hasta la vista, baby."
- Quotes before detonating a bomb that wiped out the covenant installation 'his' team was assigned as their main objective to take out.
Weapons: A pair of M7/Caseless Submachine Gun
M392 Designated Marksman Rifle
(Quotes has apparently modified his DMR to also have a fully-automatic rate of fire as an option.)
Bio: Not much about Quotes is known, or at least not to those he's assigned to.
What is known is that he's the only survivor of his ODST team, and due to whatever happened to cause this he became... mute in a way.
Designing an entire system to 'speak' for him, mainly through use of text to speech software, but also (rather ancient) sound clips where they can be fit in, and be operated by a basic, 'dumb A.I.'... Though said A.I. does have a tendency to at times give rather intelligent suggestions for something made only to run a 'speech software'.
He was assigned as protection for the squad containing 'Doktor' and 'Bouncer', due to their assigned objective being the elimination of a covenant installation on the ring.
While their mission was successful, 'Qoutes' being the one to detonate the explosives used in its destruction, all members but 'Qoutes', 'Bouncer', and 'Doktor' were eliminated before its completion.
Name: Jeremy Clark
Look:"G-guys? I-o-oh. Oh god. E-everybody's dead."
- Bouncer after the loss of his one of his teams
Weapons: Type-25 Grenade Launcher
M6C Magnum Sidearm
(Only other weapon he can store with a reasonable amount of its ammo along with the extra grenade launcher ammo he carries. (Most of which is carried in a rather large pack on his back, and only a few clips strapped to his torso for easy (albeit dangerous) access.))
Bio: Bouncer is, while one of the luckiest shot with a grenade launcher (and carrying quite an impressive number of hits to confirm it), it one of the unluckiest in terms of teammate survival. Or at least escape from injury.
So far in near every team he's been a part of he's eventually become either the only surviving, or at least combat able member. This has made many others... wary of allowing him into their squad, fortunately for him the one 'Doktor' and 'Quotes' was a part of wasn't... unfortunately his bad luck seems to have carried through, leaving only the 3 members alive.