Why are we here? Just to suffer? If your answer is "yes", then boy do I have a mod for you. 

The revenge system in the Phantom Pain will now dynamically update on a per mission basis. If you go guns a blazing in Mission 1, expect to be met with heavily armored soldiers by the time to make it to Kaz. Or if you prefer to play more stealthy, you'll quickly notice guards going from braindead stupid, to investigating insanely fast in no time.  

Here's how it works. Every mission starts as normal. This mod tracks and will trigger events that'll apply gear and abilities for all soldiers in upcoming bases found later in the mission, making each base encounter more difficult than the last.

For example. In mission 1, the first soldiers you come across are basic Level 0 guards, only equipped with an assault rifle and no additional gear, in an outpost. If you get into combat with the 1st outpost and wipe out the basic guards there, the next village will have Level 1 guards (body armor and random weapons). If you get into combat in the village and wipe out everyone, the next outpost/village will have Level 2 guards (riot gear and random STRONG weapons). Hope that makes sense. The game will adjust to your playstyle making even the early missions very difficult and dynamic.

Here are the different events that you can trigger.

COMBAT_1
How to trigger: Eliminate an enemy during the combat phase. Or wipe out an entire Outpost during the combat phase
Results: Enemies will now go up to LEVEL 1 guards. Combat abilities (hp, accuracy, reload speed, and grenade frequency) go up to HIGH. All are equipped with body armor, and one of the following weapon combinations:
-Assault/Missile Launcher
-SMG/Riot Shield
-Machine Gun
-Shotgun
-Sniper Rifle

COMBAT_2
How to trigger: Wipe out an entire CP during the combat phase. Or if COMBAT_1 has already been triggered, then wiping out an entire Outpost during the combat phase will trigger COMBAT_2
Results: Enemies will now go up to LEVEL 2 guards. Combat abilities (hp, accuracy, reload speed, and grenade frequency) go up to SPECIAL (which is better than HIGH). Outposts guards will all have Riot Gear and strong variants of their weapons (Example: Grom->Killer Bee). CPs will have 50% Level 2 guards and 50% Level 1 guards.

STEALTH_1
How to trigger: Eliminate an enemy during the stealth phase. Or wipe out an entire Outpost during the stealth phase
Results: Stealth abilities (Notice speed, cure speed, search speed, holdup retaliation) go up to HIGH. Example, by default, a guard that's suspicious will slowly walk toward the point of suspicion with their weapon down. On HIGH, they will have their weapon already drawn, and search the area with haste

STEALTH_2
How to trigger: Wipe out an entire CP during the stealth phase. Or if STEALTH_1 has already been triggered, then wiping out an entire Outpost during the stealth phase will trigger STEALTH_2
Results: Stealth abilities go up to SPECIAL

HEADSHOT
How to trigger: Land a headshot on an enemy
Results: Adds to the headshot counter. If this counter is the highest, guards will now be wearing helmets

SMOKE
How to trigger: Enemies that see smoke, or are in smoke will trigger
Results: Adds to the smoke counter. If this counter is the highest, guards will now be wearing gas masks

NIGHT_ELIMINATION
How to trigger: Eliminate an enemy at night.
Results: Adds to the night elimination counter. If this counter is the highest, guards will now be wearing night vision goggles.

GUN_LIGHT
How to trigger: Get caught at night
Results: Enemy weapons will now have gun lights

FULTON_1
How to trigger: fulton an enemy
Results: Enemies will now react to fultons at HIGH (they may shoot them down)

FULTON_2
How to trigger: When an enemy sees you fulton someone
Results: Enemies will now react to fultons at SPECIAL (not sure how it's different from HIGH, but apparently it's better)

VEHICLE_REINFORCEMENTS
How to trigger: Certain missions will call a vehicle when calling for reinforcements. Not all missions support this, but any mission that does has been enabled.
Results: Depending on how many enemies have been killed, an Armored LAV, Tank, or Helicopter may appear as a reinforcement
-If you've killed 4 enemies, a standard vehicle will arrive
-If you've killed 8 enemies, a black variant vehicle will arrive
-If you've killed 12 enemies, an oxide red variant vehicle will arrive

OTHER CHANGES
-Enemy cameras and claymore mines are always on
-Killer Bees cannot be used by enemies before the mission "Where do the Bees sleep" for lore reasons
-CPs have an infinite amount of reinforcements 
-Enemy Reinforcements will always be LEVEL 2 units (Riot Gear with random strong weapon)
-Enemy equipment will respawn upon visiting the ACC (so base satellites, power generators, lights, etc will immediately respawn)

NOTE
I have not been able to test this mod for every mission. Basically have only tested Mission 1 -> Where do the Bees Sleep. Please report bugs as you come across them