So, we had discussion fragments about the hallucinations, but I wanna talk about all of them. He game wasted good oppurtunities of using hallucinations or the mere possibility of them and executed almost all of those it has terribly.
In fact there are only three hallucinations in the game.
(1) There is obviously your true face in reflections, the subtle one in the helicopter window is great, but at the hospital it's just too on the nose for the twist. All in all there wasn't much of this.
(2) Skullface after he is killed. While it looked great, I feel like it's wasted. He could've been there from there on, occasionally appearing to tell you to embrace the bad. Just imagine you're on a killing spree and suddenly you hear Skullface laughing or your holding a guy up for a while and he starts yelling: "Do it! Kill him!"
(3) Paz. Paz was generally an interesting idea and I liked the conclusion. However Miller and Ocelot appearing was just dumb cheating to throw us off. Just let her be there, explaining that she surived and have Venom not question that at all. He isn't talking much either way, so it wouldn't be that unusual. It would also nice to have glimpses of her on MB. Like looking at one of the posters or just walking around an edge with her vanished when the player goes around that one too.
(4) They messed up the Man on Fire, Mantis, Ishmael and Skull potential. The problem is that the effect on their surroundings made very clear that they existed. Ishmael should never shot anyone, but handed you the gun for apparently no reason. Nobody should've reacted to the man on fire, just to sudden bursts of fire that could also be just the hospital on flames and some chemicals or something. And the Skulls, mna the skulls. They should've been teased early, but only used from the middle of chapter 1. Just imaging mist appearing and just glowing eyes that wander through it. The Skulls surely have other dutys and would maybe not care for you at the early points of the game. Just imagin mist and hlowing eyes and boss asking what this is, but neither Miller nor Intel can see anything through the mist.
The idea of not knowing what's real and what not could've been explored very vastly and to great effect. I repeat my suggestion of MB as a mind palace.
(a) Motherbase could be a actual base and a dreamworld at the same time with Venom wandering of in unfinished rooms to dream. You could unlock and visit different rooms with past memories. Just imaging entering a room and suddenly being in a remake of an MGS3 bossfight. Like this old missions could be entered too, signififying how Venom just remembers them in a way. And in fact, you could remake stuff from old games slightly wrong. Like have The End, but his dark skin on his head is in a wrong pattern. Have more people lole Paz who may or may not be there. Have Strangelove there until you hear that she left the base. Mix that with people from that are actually here like Miller and Huey for maximum effect of not knowing what's going on and what not.
This could further explain why Venom is so silent. After al he doesn't know what is going on half of the time and he rather waits to be sure.
(b) Make more of the demon system. Somebody suggested this in the last thread. Have dead people appear like decoys when you have too many demon points. They would look like normal people, but would have no stats and would vanish once you hit them wih anything. Have on the other hand have friendly ghosts appear when you goy little to no demon points. Occasionally a shadow of Boss or Zero appearinh pointing silently to the location of a diamond or a blueprint would be cool. Or imagine ghost soldiers of your dead appearing who stay guard as you escape in a helicopter when the enemy is on alert. They wouldn't do anything. Just be there showing how much Venom values loyality.
(c) Have characters in general appear as Venoms thought process, showing that he is silent, but listening. When somebody asks Venom let different people appear behind him, giving their comments. When something technical comes up let Huey and Strangelove appear, when it's about surviving Ocelot and the boss. And make sure that absolutely nobody appears when something medical would come up.
(d) Regular ghosts of characters, dead or not, could also make the fanart ending with Venom dying in Outer Heaven and Quiet appearing? Is she a ghost that comforts Venom? Is she taking him to heaven? Or did she survive and is saving him and he lived some happy days with her in secret? For the player to decide.