Call of Duty: Black Ops II

Story related achievement. Can't be missed.

This achievement will unlock after completing the eighth mission "Achilles' Veil", no matter what difficulty you are playing on.

Note: "Ultimate Sacrifice" achievement is also obtainable during this mission.

---
I'm not taking credit for the other solution, that's why I'm only putting a link and not the complete solution.

Mission 8 - Achilles' Veil - Story progression achievement, cannot be missed.

Mission Challenges

1) Destroy 20 quad drones - There will be quad drones all throughout the mission. Any kills done by AI friendlies will not count towards this challenge. After the VTOLs crash Menedez's speech, stick around in this area to eliminate as many drones as possible.
2) Eliminate 20 enemy soldiers with a sword - After you pick up the optical camo, challenge 3, head to the left of the courtyard and process that way to the next waypoint. You will see an access point to the sword.
3) Melee 20 enemy soldiers while using optical camo - You will find the optical camo in the same building as intel #1. It will be in the next room up from the intel. From there, melee kill 20 enemy soldiers. You can also complete the 2nd challenge in tandem when you have the sword.
4) Destory 8 quad drones with a turret - When you reach the area with the ASD, there will be a gate on the right side of the map that you can gain access through that will take you to the turret. These kills will also count towards challenge 1.
5) Eliminate 5 enemy soldiers by exploding vehicles - There are many enemies and vehicles in the area with the ASDs. Make sure several enemies are around a vehicle and destroy it. You can use multiple vehicles to complete this challenge.
6) Destroy 4 enemy ASD while they are disabled - Make sure you have EMP grenades and refill your ammo when possible. There are only 5 enemy ASD drones in the area.
7) Eliminate 5 enemy soldiers using the VTOL gunner - This challenge can only be done when you choose to shoot Menedez after the VTOL with Harper is shot down. Please read the 'Ultimate Sacrifice' achievement description below.
8) Direct quad drones to eliminate 25 enemy soldiers - After you gain control of David, you will be able to order the Quad Drones to attack particular enemies. You will simply need to have them attack in a general area where the enemies are.
9) Collect all three intel - The first intel is located in the same area where you initial start challenge one. There is a staircase on the right side of the courtyard that will take you to an upstairs room with the intel. The second intel is located in the room to the left after you come out of the narrow ally when playing as David. It will be located behind some furniture in the right corner of the room. The third intel is located on a roof of a building just before you reach the bridge to cross where Menedez is located.
10) 100% survivability - Complete the mission without dying.

'Ultimate Sacrifice' is earned in this mission. You will run into a short scene with Mendez where you will be given the option to shoot at Mendez or Harper. You can still earn this achievement by not doing either of them. If you wait 20 seconds, Menendez will shoot you, Farid, and the achievement will pop. Either way, you MUST shoot Menedez for this achievement(Video Time: ) To point out that if you plan on going for the 'Showdown' or 'Good Karma' achievement that you MUST kill Harper since Farid is needed for the achievement. A good way to get 'Ultimate Sacrifice' and ensure that you can earn one of the other two is to shoot Menedez and then after the achievement pops, save and quit to go back to the previous check point and make and choose to execute Harper.(Video Time: 8:17-9:59)