The hardest part of this level is actually getting or figuring out how to get the White mamba down. It gets more difficult when the objective is to do it without him resisting. Also to S-RANK you should go for that same objective or you will lose lots of points.
100% Extract the White Mamba.
100% Extract White Mamba without resistance from him.
100% Extract the Prisoner held at the child's camp.
100% Secure the diamonds at the camp.
100% Extract 20 or ALL child soldiers.
Objective 1 is easy enough because it is the main mission. I would run through it however you would like and get a good idea how to take down Mamba. Best way for the first run is to let him come at snake. Quickly hit the trigger prompt and counter him several times this way until he goes down. It takes a few counters.
Next we want to extract the white mamba without him resisting. The problem I had was that I was using a MODEL 2000 NL sniper rifle. Non Lethal- NL. I did not realize how long the rounds take to put the target to sleep. I got caught this way.
I suggest in turn, to stay by the end of the pier. Near the yellow metal construction and a bit behind the burnt or broken down hut. You should be able to peek at Mamba from there. Snipe him with the MODEL 2000 NL. Then wait a bit. Go up and extract.
Another method would be to go ALL non lethal. Pick off each child soldier one by one. There are 20 in all. You can snipe them and as long as they do NOT go to COMBAT mode White mamba will NOT move from starting location. So once again you do not have to always used suppressed shots here. Although they are recommended.
Once all children are down you can extract them all and still will be Mamba. Then you can go by the sniping area from earlier Or you can get a closer shot. Either way just extract him and that will be 3/5 objectives.
The diamonds are easy to find i forget exact location and I apologize but they are either near the prisoner or without a doubt in a very easy to spot area in the village. I apologize the footage was lost. Bring D-Dog for the prisoner if still having trouble. 5/5
Finally for the S-RANK. It would probably take very long to eliminate all the child soldiers. So what I did was from village starting point using sneaking suit of course stay towards the right or East. Eastern part of the map until you can get to that sniping point again. If there are some children in the way, use windurger or riotsmg. Please make sure to have full suppressors this time for the S-RANK. Snipe the white mamba with a SUPPRESSED Model 2000 NL sniper. Wait a bit until he goes to ZzZ. Then there should be 2 child soldiers you must pass after that. One on the entrance to the bridge and one on the ship. Windurger them, then extract the Mamba.
* You must have child extraction Fulton for these objectives *
* Wormhole is highly recommended. *