Clues that Q is Delta, the 4th particpant:
1) Literal shadows from Delta in most Q team scenes (
here are the shadows from Pop-off, for example).
2) "The old man in the wheel chair" dialogue
3) If you try to select "Q" in the "who to shoot" scene, it will say to select Q's real name. If you input "Sean," it will give an error. If you choose "me" or "myself," the game will say "you cannot commit suicide." - Credit for expanding this goes to overchargext
4) If you say that "Q" killed Mira, Eirc will say "that's impossible!," and if you select "Sean," or "me," he'll say "I knew it was you!" - credit for expanding this goes to Ro9ge
5) "The truth is invisible" anagram
6) The parasite discussion
7) Carlos/Diana not knowing why they pressed the decontamination button, or the bad execution choice (mindhacking). Sean never claimed he didn't do it, as he can't be mindhacked.
8) The anagram about the 10 that Akane finds
9) The scene after the radical 6 is chosen to not be injected where Eric talks to Gab and calls him "Old man," he is actually talking to Delta. Both Eric and Mira are looking to the screen (to Delta), and Sean asks if they could speak. - Credit goes to untuned of the Something Awful Forum, and to Ro9ge for elaborating.
10) Q never has a portrait in the status screen, but there is one of Sean inside the Study - Credit goes to YoshiOfYellow of the Something Awful Forum
11) "Even Q ... he couldn't see or hear when" (when talking about Q team execution) - Credit goes to voltcatfish of the Something Awful forums)
12) Sean in Pop-off says "you are all really important to me" rather than "you both are really important to me," despite the fact he only knows Q team.
13) When Zero tells Sean about the "old man" who visited him.
14) Eric says "I know the leader's supposed to decide who to vote for but...", because Delta is believed to be blind and deaf - Credit goes to Ro9ge
15) Eric is suspicious of Sean because he isn't on the X-passes - Credit goes to Ro9ge
16) If you try to shoot Mira, she will shoot twice before the X-pass notification comes on, because she also shoots Delta - Credit goes to Ro9ge
17) Despite the fact that Carlos seems to know Q, he doesn't recognize the robot that looks like Sean - Credit goes to zatchel1
18) Towards the end of the C-team ending, when listening to the recording of Zero, Zero specifically says that he's dead in this timeline, and that Carlos executed him. This is also the timeline in which all of Q-team dies because Carlos decided to execute Q team. - Credit goes to Ro9ge
19) After Phi and Delta and delta are born, the status screen shows Q and Phi alive.
Status before birth and
status after birth - Credit goes to YouWithTheFace
20) Decision game starts with "deci," which means ten - Credit goes to ultramario1998.
21) When Sean decides to stay behind after pressing the Decontamination button, he is staying behind for Q, and it becomes clear with close examination that Q is also chained, and Q is the one staying behind. Sean is looking at the Camera (at Delta) when he says that he stayed behind because of him. And when they try to unchain Q, they are always trying to get it off the pole, and not off Gab's paw.
Here is an image that demonstrates this.. - Credit goes to Ro0ge, and BloodTrain for the image.
22) In the ending of the VLR timeline, Sigma asks "a child?" When he sees Sean's corpse, despite the previous indications that he knew Q was handicapped in another scene. Q doesn't show up as dead in the status screen. - Credit goes to Thisisalsomypass
23) Generally, throughout C and D team fragments, they indicate they know Q at least somewhat, despite the fact that if you win the coin toss, it is revealed that no one seems to know Sean. - Credit goes to Ro9ge
24) During "You are Zero," if you choose the identity of Zero wrongly, after Sean is dead, Eric shoots 3 more times despite the fact that only Diana and Sigma are left, and Gab is revealed to not have been shot. There is a pool of blood that appears as the camera zooms out. - Credit goes to RenegadeReaper, with additions from Bookeworm and TheNarcor
25) When Q team is drinking at the bar before the vote, there is a glass to the right of Sean, and since Eric and Mira already had drinks, and Sean can't drink, it must have been for Q. - Credit goes to blankemp
26) One of Q's X-passes is "age," and another is "self." Thus implying that Q is the "old man" people mentioned, and Q is zero's "self." Also, another X-pass is "eye," which refers to that he is the one watching them all. There is a 4th one (take a look at 37 for more info) - Credit goes to -tjm-, with an addition by Bookwurm.
27) When the Crash Keys twitter account was revealing the images of the participants of the decision game, they never revealed Sean. - Credit goes to TechnoSyndrome
28) There are a lot of Xes. The X-door, X-passes, etc. X is the roman numeral for 10. - Credit goes to BloodTrain
29) In the C Team Execution Decision fragment, Carlos calls out for Mira and Eric through the vent, but not Q (he is believed to be deaf). Credit goes to Lumsyl.
30) When Q team goes to sleep, there are 4 thumps, not 3. - Credit goes to GFJmember
31) When Carlos seems to know Zero's identity in the beginning, it is presumably because he notices that there is one person missing (Q), so he makes the connection. - Credit goes to demosfera
32) When at the Bar before the execution, and Sean asks where they were, they mentioned that "We all lived at Dcom. C team and D team were there too." Rather than "Both of us lived at Dcom." - Credit goes to Jetstream_Kage
33) The segment called "triangle" where there is a stand-off between Sean, Eric, and Mira. The Greek letter delta is a triangle. - Credit goes to soraku392
34) How obsessed this game seems with 3. There are 3 teams (all of which we think have 3 members). There are 3 survivors of the VLR timeline (without the time travel shenanigans). There are 3 x 2 shifters in the game. Biolab has 3 syringes and 3 fingerprint sensors. This is the 3rd game in the series. Delta, as mentioned, is a triangle symbol, with 3 sides. Can anyone think of anything else to add with 3 in the game? - Credit for this is split between me and gschmidl. Credit for corrections about me including Montehall goes to stordoff, aunt_snorlax, and swimmerwoad
35) In the
logo, there is an IV, where the 6 is supposed to be. Delta is the 4th letter in the greek alphabet, and what Q is (the 4th member of Q team) and if you add up the 4 and the 6 that is supposed to be there, you get 10, the number of participants. Credit goes to ScLobsters, and to AlexHusky for expanding it.
36) In the execution of Q team, there are 3 piles of flesh in the shower, despite the fact that Sean is a robot. Credit goes to Dastev.
37) After the "don't shoot" option in Triangle, if you pay attention to the X-Pass board, you will learn that Q had the X-Pass "BRO," which obviously hints at him being Brother. An image of it can be found
here. Credit for finding this goes to granolaman
38) When Sean is hacking the Quantum Computer, the screen flickers, as Delta's glasses get interference due to hacking. credit goes to Warbec
