My game has very large side mechanics that involve picking up new party members along your journey and choosing who you travel with. You'll get opportunities to appeal to certain active party members through dialogue/actions/choices and will increase a variable with each called "bond". At different intervals for everyone you'll get unique dialogue whereas the characters open up to the protagonist more, unlock unique personal backstory quests or eventually even unlock new skills/equipment!
PTSD and other mental illnesses aren't a big theme in my game but I do wish to implement it in a potential party member named Aiello. He is a very intelligent, skillful and kind hearted man who is contracted to a nation's capital as their lead producer/designer for firearms and explosives. (In this setting, firearms aren't stuff like M4A1-S or anything it's like Pipe Rifles and steampunk-esque!)
His self esteem is largely attached to his intelligence and his crafts, as they are the main source of compliments or attention he really gets. He solely contracts himself to the capital because A- They pay well and B- He simply doesn't trust other people desiring his goods with good reason, which I'll touch on.
Spoilers, of course, for anyone looking back on this who is interested in my project. Specifically spoilers only relevant to the bond quests of Aiello and the nation history of Fastigium!!
Through travelling with Aiello, your bond will increase to the point where he opens up about a huge guilt that he holds. He is confident in the notion of showing the protagonist as he has built a trust with him to a point where he understands that he simply must know what he is responsible for and also to get it off his chest, or just to finally talk about it with someone.
He wishes to take you deep into some mountains that are out of the way in the country of Fastigium. He is confident and direct in his intentions to take the player to a "Long lost and forgotten town that is now drained of hope". On arrival, he does announce that they are at their destination. It's clear he wishes to begin teaching the protagonist what happened to the city in a calm, collected, cool manner but since they enter, he quickly begins to break down and becomes overwhelmed with emotions.
Over the course of this interaction, the player can push out of Aiello that he had once constructed the most large explosive device he had ever heard of. It was a massive success and he had grown proud of this achievement, but only worked on a "need to know" basis at the time. He never inquired what it was for, but he certainly knew it was great enough to take out an entire town if it really wanted to. Of course, he had sold off his creation and not long after, found out where it had gone. He hurried to the mountains but missed the giant explosion that been felt through all of Fastigium. He investigated with proper equipment later and found that the entire town had been destroyed.
Because of everything surrounding this, he is very conflicted. He really desires to be proud of the bomb, which was supposed to be his crowning achievement, but he struggles to feel that way. He's about equally mad at the contractor and himself, feeling as though they were equally responsible for the deaths of so many people and he mourns over the dead that would later be forgotten by much else of the world, fading out with irrelevance of an already dying town (due to trade being limited due to their isolation).
Now, this post looks kinda ranty and long in perspective and I thank you for holding out with me! I understand that mental illnesses do not just "happen" and I'm curious on basically any factor involved with knowing if my design behaviorally feels appropriate for my Aiello character. I understand too, that this case of PTSD could have been caused by the years of dwelling on the incident and obviously wouldn't have happened immediately, though, sudden traumatization certainly may have happened.
Normally, he is happy to discuss his designs and overall profession and view on world events as, again, this is mostly what he gets his self esteem from, almost like he feels it's really all he's good for. Maybe his devotion to Fastigium could be a sense of obligation? Like a silent apology to the country for what he views as his fault. Of course, he's not open about his involvement in the incident out of fear that he will get locked away or killed for his involvement as well.
I am a straight, white male with no mental illnesses and so I'm in a lot of majorities here haha. I don't want to be insensitive with my inclusion of Mental Disorder as a surrounding trait in someone's backstory and a piece of world history. Thanks for reading and I'd love to hear your honest opinions and critism. This is all still open for change!