Hey, I’m am stuck on truth and reconciliation on legendary I have to say I have never struggarld with a mission untill now. I get to the bridge and kill the three elite swords men but soon after the story mode talk before I can move the captin gets killed. Any help at all someone could please give me.
As it’s an FPS I’m not sure how we could help you (without playing FOR you). It’s all up to you, really.
Try different tactics, and try to take a few rounds for the Captain. It’s better that you get hit than him, considering that you’re the only one with personal shielding. If the checkpoint just truly proves to be a “mission impossible” situation, then I recommend you just restart the level (or spam revert to the last checkpoint, as it eventually may throw you two checkpoints back) and just try to avoid getting stuck into that same situation.
As the Captain and the other Marines have no energy shielding, as said before by Jochon, you should take SOME hits for him.
A good thing to do is USE PLASMA related weaponry, best choice PLASMA RIFLE as it is the most effective weapon against Covenant.
Tackle the Grunts first, the the Elites (Grunts are LETHAL in packs with Plasma Grenades).
Make sure you have GRENADES and an Assault Rifle as backup, you shall find some on the raised platform in the middle of the bridge.
Any other questions, add Maverick CT59 on Xbox LIVE.
Hope this helped 
Storm through the hallways, Marines are slow and can’t keep up so that’ll keep them out of danger.
Plasma pistol for Grunts and Elites, Plasma rifle for Jackals and Hunters.
Conserve your frags and use plasmas more.
During the grav lift battle, fire a shot so the Covies come out the doors quicker. Throw a plasma grenade.