Im one of the lucky few who has earned "A Monument to all your Sins" i finished Sept 15th at 12:37am and it was a very difficult exp. I even ran out of ammo and fought two hunters on the last level bare handed. The tips are easy: !. Elites have that name for a reason: They can, and WILL, kill you with very little effort and since playing on Legendary means you will fight maybe half a dozen Elite minors that leaves the majority to be Ultras if not Zealot class. Plasma weapons are your friend in this case as Ultras and above have powerful shields that can sometimes take more than 2 plasma overcharges to beat but there is a way. First soften them up with grenades if u have plasma the better since it will knock down their shields better than Frags will. Then hit them with plasma if you can not use a plasma pistol use a repeater or rifle in its stead. And then finally go for the killing blow, use precision weapons like the DMR or Needle rifle to take down with one shot. However, while the DMR is a awesome instrument of death, the needle rifle does have the added ability of the super combine which will help when you are either in a bind or you arent quite proficent in your headshot abilities quite yet. 2.Be aware of your surroundings: Bungie has designed Reach to give you a fighting chance aganist your enemy sometimes going down the wrong hallway could lead you to an ammo box filled with Grenade Launchers or health packs. Take mission 3 for example, when playing on Normal, most people just run forward not requiring much cover since Noble 6 is a living breathing grim reaper and they just mow down the enemy to get to the target locator and continue the level. But this does not work on higher difficulties. If you took the high road to the left and continued down the terrace you will notice a Sniper rifle with decent cover to deliver enough firepower to take down the big Elites in the area before moving on. 3.Pick your battles wisely: Just because you can fight, doesnt mean you should fight. There are many ways to handle the enemies in Reach but going in guns blazing isnt one that will keep you alive long. I recommend using the terrain to your advantage. There are multiple levels where large groups can be bypassed in order to complete your mission and the 3rd Mission of the game is one very level. While it may seem to agienst nature to NOT fight sometimes getting around your enemy so you can get yourself better equipped or have better ground will help you in the long run. 4. Control, control, control: Learn to pulse fire or burst fire your automatics. Now with the new recoil system, firing fully automatic without any breaks will just lead to you wasting your ammo (unless they are within spiting range in which case go CQC and then pump them full of lead). Fire in short 4-5 round bursts this will ensure accurate shots and conserve the very limited ammo that you will find. Another thing is to control your own impulses. The melee attack isnt what it used to be as it will not kill an enemy if its shield's are up and most of the bigger enemies (Elites,Brutes,Hunters etc...) will not die from just one melee hit and since melee strikes not have delay between them it will be hard to fend off an attacker if your shield's are down and your melee has failed (most Ultra's can kill you with just one melee to your unshielded body). Might I suggest using your melee and then hitting them with fully automatic fire while aiming at their upper torso this will ensure the full amount of damage is being done to them. 5. FORKLIFTS SUCK!!!!: DO NOT USE THEM NOT EVEN FOR COVER AS THEY CAN AND WILL EXPLODE SINCE ALL ENEMY AI BOTS ARE GRENADE SPAMMERS AND THEY LOVE TO SET BIGGER THINGS ON FIRE!!! 6. Use your armor abilities...correctly: Each armor abilities has its time and place. Sprint is obvious from getting to point A to Point B fast without 4 wheels, Armor lock makes you invulnerable to harm but because the AI is alil smarter than you they tend to stand at a reasonable distance and wait for you to unlock so they can unload on you in masse. The most useful armor ability is Drop Shield. Not only is it a portable health pack, but its also a backup shield. When your shields drop and there are enemies in front of you, activate it and run out the back of the shield for better cover or you can wait inside till your own shields recharge until it either runs out or the enemy takes it out. I recommend the former rather than the ladder as it puts you in full control of the outcome since your facing the enemy on your time not theirs. Those are some basic tactics that I used to get the achievement. If anyone has any other suggestions I would love to hear them get a nice discussion going. If its just troll responses I will not pay attention and ignore you.