okay i keep thinking about the bridge scene. i'm motherfucking talking about that damn bridge scene again.
its so clear to me that TJ and quincys care for each other is mutual. while it may seem like quincy loves TJ so much more because hes the one doing all of the legwork during icyridge it's so implied during the entire arc that he means something to TJ too or else anyone could've been able to talk him down from his arrogance.
i mean. god. he literally says it here that the key hunt, carrying out what he believes to be his purpose, is the only reason why they can't be friends. he WISHES they could be friends but he thinks it can't be possible because feelings might get in the way of pursuing his goal and so he's afraid of getting attached. his sudden cruel treatment of others makes total sense if this is how his mind operates. it's why he tries to pretend he doesn't care, even though he clearly does.
this is such a loaded fucking scene.
in a way you could say TJ was testing quincy. try to piss him off or bum him out enough that he'll get sick of him and give up on him like he believes everyone else has. he expected anger, disgust. but he's forced to realize that every single thing quincy's done for him or said to him is genuine. that it wasn't for any self-serving reason, but because he cares. genuinely, truly cares. and it's too clearly the truth, so he accepts this now and drops the act entirely.
that "thanks" probably accounts for so many different things. thank you for listening to me. thank you for not leaving me behind. thank you for caring about me. thank you for not giving up on me. thank you for continuing to believe in me. thank you for being my friend.
that unconditional kindness, not leaving someone behind no matter how difficult they're being about it, was the same thing TJ had so naturally done for quincy. he's so adamant about saving him and getting him back because he's been through the same thing and knows it's all an act. he so strongly believes TJ has a good heart because he's seen it for himself firsthand, even if it's not as obvious to us as the player.
TJ is so used to believing that his life being meaningless is an undeniable fact. it is an unshakeable part of his logic. being cast aside and being left behind is something he fully expects and anticipates. and quincy's just told this man that he matters so much to him and is so special to him that he'll never leave his side no matter what he may say or do in the future. if he means this much to at least one person, his logic is essentially flawed.
all this is to say that their relationship is far from one sided. quincy is clearly eternally grateful to TJ for giving him a chance, and while he's not as obvious about it, and (probably) wouldn't turn into an interdimensional serial killer without him, it's clear that TJ is just as thankful to have quincy in his life.