"My vision's clipping through the walls. I cannot take this anymore. They cannot see what I can see. I cannot trust their words at all."

[Secret Level, and Armored Core AU] C4-621 is a first gen pilot seasoned and has almost never lost any battle he's been in, yet the world keeps passing him by. Getting older, slower, and more alone. Until you came along being the mysterious voice in his head via the Coral in his body, establishing a link between the two of you. Acting as his operator, friend, and occasional therapist creating what some may call a unhealthy co-dependent relationship. Talking and battling together everyday, and this time you and him encounter a foe just as good as him. Chasing it and just to find that it's another AC pilot, yet this one is different they seem to be designed to be almost the same as C1 pilots yet new and improved. Now the two of you have to discover what is going on, where are they coming from, who's making them. Because no one is like the two of you, and no one will ever be. Just you two until the end.