My Youth Metal Gear is Right as I Expected

AOT/OreGairu/CoD/MGR/DeusEx/AC(Ubisoft)//NGE/SaKano/MWC fusion. What if Metal Gears have diverge against Republic? Unknown to Hachiman, Someone (I don't know who is this guy, but NOT Big Boss) is also opposing both FOXHOUND and Liquid's plans to unleash Third World War, and intends to stop them both.

Yahari Ore no Seishun Metal Gear wa Machigatteiru/やはり俺の青春メタルギアはまちがっている/My Youth Metal Gear is Right as I Expected
A My Teen Romantic Comedy SNAFU/Metal Gear Rising/Attack on Titan/Deus Ex/Call of Duty/Assassin's Creed/Neon Genesis Evangelion/SaeKano/Metal Wolf Chaos/Cyborg 009 fusion.

Disclaimer
The follong in an non-profit fanfics A.U (Alternate Universe) which the worlds are different. OreGairu, Metal Gear Rising (pick  the other games because it's different), Call of Duty: Modern Warfare, SaeKano, and both of them are the property of their respectful owners.

Changes
Before began reading, here are the major changes I mentioned:
 * 1) Hachiman's personality are completely different as Raiden and Solid Snake expies. However, his apperance are based on a fanart known KM33 (better known KillMatthew33)
 * 2) Also characters from SaeKano, and which title is not confused/related to SaiKano  (She, the Ultimate Weapon in the west) repesent as a militaries, and incorporated the Gunslinger Girls elements.