Did he buy Ali ramyeon and a bus ticket home as a token of gratitude for Ali saving Gi-hun? After all, Sang-woo sincerely warned Gi-hun to get moving during "Red light, green light" and looked worried when he saw that he had made it over the finish line, but Gi-hun hadn't.
He and Ali said they could win, split the money, and give it to their families. Was Sang-woo doubly despondent after betraying Ali that he knew finding Ali's family to honor his promise would be nigh difficult given his wife and son are in Pakistan? When he was shouting at Player 069 (the man who had lost his wife, Player 070) to get a hold of himself, was he really projecting his own guilt?
Did he really fall asleep in the penultimate episode, or was he pretending to so that he could lure Gi-hun over and kill him?
And did he already plan to kill Sae-byeok, or was he just woken up by Gi-hun's yelling and decided to take advantage of Gi-hun being distracted?
Did he sincerely view it as a Mercy Kill considering Sae-byeok was already dying and deliriously begging to go home?
Did he kill himself after losing to Gi-hun in the last game despite the latter's offer to forfeit the game together in order to atone for his previous actions, or was it because it would be more shameful for him to let Gi-hun walk away with nothing after clearly winning the game, despite all everyone had been through, so he did it in order to let Gi-hun keep the money? Or was it that despite his tough talk, he simply could not live with the guilt of getting Ali killed, as well as murdering the glass blower and Sae-byeok, added to the shame of leaving his mother penniless and himself facing jail? A mix of all of that?
The Front Man:
It's never explained why In-ho, after experiencing the game as a player, would willingly take on the role of a substitute host to Il-nam, even personally shooting his own brother to protect the system. Has he resigned himself to the power the wealthy have over the poor, choosing a role where he could at least try and maintain fairness in their sick games? Does he buy into Il-nam's claim that the games aren't inhumane because no one (guard or player) was forced to participate or unaware of the rules they're bound to follow? Was he broken into nihilism by his experience as a player? Was it just a matter of money (considering In-ho was shown to have lived in a rundown apartment and couldn't even make rent)? And did he intend to kill Jun-ho or did he purposefully shoot him in the shoulder so that his Disney Death would provide a small chance to escape?
While the Front Man believes in giving the players a fair chance when playing the games, he often overlooks when those players (or even his own men) cheat (e.g. killing the other players directly), only stepping in when it seemed necessary, such as when the riots got too much for Il-nam's liking or when Player 017 made the Glass Stepping Stones game too easy for the VIPs to enjoy. Could it be an extension of giving his players a chance by giving them an "anything goes" clause, perhaps due to his own past experience as a player? Is it him giving into the nihilism and making the players kill each other because that's how he sees the games? A special case could be made for when he stopped the bonus game on Il-nam's insistence, as him keeping the rest of the games a secret and killing the guards helping Player 111 soon after could be interpreted as him realizing what he had done and stopping as much of the bias as possible.
It's possible In-ho played the game and won a huge amount of money, then poor spending habits continued and he wound up back in debt (which is Truth in Television for many people who win the lottery); he may have attempted to contact Il-nam and Co. in the hopes of getting back into the games for another windfall. Maybe he was then told as a returning contestant (and by extension returning winner since everyone who doesn't win dies) he would have too much of an advantage, so he was offered a role as the Front Man.
Il-nam, who created the titular deadly games, is a reprehensibleperson no matter what, but he still has plenty of this when you look closely enough.
With regards to his actions during the games - were any of his mental issues real or was it entirely a show? When he plays in the games, is his life in any actual danger, or are things rigged in his favor? If so, is this to level the playing field for him, since his mental/other issues would leave him at a massive disadvantage (For example, Parkinsons would make Red Light, Green Light and Dalgona very difficult, and his frail build would be a near-death sentence for Tug of War).
The marble game's losers are manually executed in a way that allowed him to fake his demise, suggesting that this was always intended to be his exit from the games in preparation for the VIPs' arrival. The previous games, however, were held in ways that would have meant his death had he failed beyond reasonable leniency, most notably with Tug of War. He says that he joined out of a desire to experience one last round of competitive spirit, but was he also a Death Seeker hoping to end his life in a way that didn't feel like surrender?
How real was his friendly persona? He seemed to genuinely grow fond of Gi-hun but by how much? During the marble game, did he give Gi-hun the win purely to make a quick exit, or did he also want to see Gi-hun win the games?
Why did he seek out Gi-hun specifically after voting to end the games in "Hell"? They share a drink, and Il-nam mentions he's returning to the games, because real life may as well be a hell with him not having a home in town or a place to go. (The penthouse revealed this was Exact Words since it's in another district.) Gi-hun even jokingly tells the old man that he came back because of him and orders him not to die. Was Il-nam giving Gi-hun a reason to rejoin the games, or was he sincerely curious about his life?
Why did he really decline to take part in the viewing party for the final games? Was he really uninterested after experiencing the greater thrill of participating? Was exhausted from the experience and feeling unfeigned symptoms of his cancer? Did Gi-hun's attempt to cheat at their final game leave him too upset to want to see him? Or did he feel Curious Qualms of Conscience about watching players die in his "fair" games when he had "cheated" his way out of the consequences of his own loss?
Why did he choose to break Gi-hun out of his Heroic BSoD in his last moments? He had no incentive to, since the effort was literally killing him and Gi-hun in this state was not a threat to the Games. Could it be that a part of him respected that Gi-hun didn't want to spend the money he had earned from other people's deaths and really was in this to save his mother?
As YouTuber Heavy Spoilers points out in this video, his final wager with Gi-hun in the Season 1 finale can also be subjected to this - was it just a method of vindicating his Humans Are Bastards views, or was it his own way to teach Gi-hun a lesson of some sort and get him to perhaps use his money for a better purpose regardless of who won?
Him not sharing his name with his Fire-Forged Friends in Episode 4, but telling it to Gi-hun in private in Episode 6. Is it truly because his dementia and the growing brain tumor made him temporarily forget it, or did he once again overplay his illness on purpose, because he was worried that one of his new friends might recognize the name Oh Il-nam, figure out that this fabulously wealthy old man has no place in the games, and start unraveling the lie?
Is Gi-hun really a good person, or is he a cowardly hypocrite who lets others do his dirty work? For all his moralizing, he never tries to get others to vote to end the game until the only one left is his childhood friend.
Was it realistic for Ali to trust Sang-woo to hold his marbles, however briefly, or was it a major case of Idiot Ball? While Ali is established as the most loyal and trusting member of the main group, some viewers found it hard to believe he would be that naive to hand Sang-woo his literal lifeline, especially given how Sang-woo was clearly losing his own marbles in the lead-up to the switch.
Was Player 017 in Glass Stepping Stones really hiding his knowledge to get rid of his competition? While he admits it was a self-driven reason, he also implies that he wanted all the most dangerous players dead before proceeding.
Also, did he really not know which of the last two panels was tempered, or had he deciphered it already and was just stalling for time so that he could make it at the last second and the others would all fall to their deaths so he could walk away with the money?
, his final wager with Gi-hun in the Season 1 finale can also be subjected to this - was it just a method of vindicating his Humans Are Bastards views, or was it his own way to teach Gi-hun a lesson of some sort and get him to perhaps use his money for a better purpose regardless of who won?