Jason being immortal but itās kinda like Klaus from the umbrella academy in the sense that he doesnāt fucking realise that heās immortal. Damian is the only one who knows and itās been pissing him off for YEARS that Jason wonāt get with the fucking program.
the thing is, Jason never questioned what exactly woke him up back in that coffin. he was slightly distracted by dealing with the wood and dirt attempting to suffocate him back beyond the grave, and once heād gotten free and was wandering around Gotham, he didnāt have the presence of mind to do much but zombie-walk around until the league found him. after that? well he was too busy with training, annoying Raās, helping raise Damian, and just overall getting used to life without being Robin to think about the fact that heād come back to life at one point.
Damian, on the other hand, clocked that Jason was immortal as a toddler when he watched his new older brother accidentally fall off a cliff during a ānature hikeā that was actually endurance training that Damian had been allowed to attend from a chest harness that, luckily, he hadnāt been inside of during the fall. he peered off the edge of the stomach clenching drop, sharp spikes littering the bottom, to see Jason un-skewer his shoulder from a rock and stand up to crack his neck, before casually calling up that he was fine and it was ājust a little fallā. little Damian called bullshit.
things continued like that the entire time Jason spent at the league, and it pissed Damian off to no end that Jason kept just walking off fatal injuries and absolutely REFUSE to believe that they were fatal. āi just have a high pain tolerance.ā āyou got shot in the neck, ahki.ā āit skimmed me.ā āYOU DIED.ā āstop making up stories, demon brat.ā itās driving the kid insane. the worst thing is he canāt even tell anyone else for fear that Raās gets a hold of the realisation and decides to use Jason in his research for finding better ways to prolong his lifespan.
Jason, bursting into Damianās room in the early morning, spurting blood from an arrow wound to the chest: Dami- Dami- u- argk-
Damian, half asleep, watching blankly from bed as his brother bleeds out on his floor:
-twenty minutes later, Jason wakes up on Damianās floor completely healed-
Jason: wow, sorry Dames, guess i drank too much last night and blacked out. didnāt mean to crash here.
Damian, unimpressed and holding a bloody arrow: grandfather says you stopped an assasination attempt on my mother.
Jason: haha yeah, craaaazy night
eventually Damian heads to Gotham and, of course, his overprotective immortal brother follows soon after with the mission of building a crime empire, killing a clown, pissing of the fourth Robin at any opportunity, and infuriating the fuck out of Bruce Wayne. after a while the Red Hood gets his identity reveal, and gradual tentative truce, and Damian gets both of his families to be more or less on ok terms for once.
the issue is Jason is still really bad at staying alive. and the rest of the family is kind of sensitive to that specific thing. and Damianās apathy is not appreciated. it takes them a while to figure everything out.
*all four batboys are captured by a rogue, Bruce on his way but they need to stall*
Rogue: and now, you will have to pick amongst yourselves who will DIE!
Jason and Dick, instantly: ME!
Dick: ITS GOTTA BE M- Robin what the fuck
Jason, so used to Damian being weirdly ok with his more dangerous activities heās not even offended: YEAH SHOOT ME. I CAN TAKE IT!
Tim: no he canāt, donāt shoot him!
Jason: bite me non-believers, iām getting shot today-!
Damian: please do it quickly so he shuts up.
Rogue: the others told me the new Robin was fucked up but like i didnāt realise exactly how much-
Tim: me and Damian didnāt really get off on the right foot, on account of he kept trying to kill me.
Jason: ? so? thatās just what he does when you piss him off. he tries to kill me all the time.
Jason: i called him a wanker last week so he shoved me off a building with no grapple. luckily the garbage can broke my fall and saved me haha!
Damian, fully never wanted Tim dead and was instead so used to never having to worry about hurting Jason that he forgot that murder was actually fatal to his other brothers: yeah thatās my bad, Drake. it was instinct.
*Bruce walks into the batcave to see Jason, gunshot in his forehead, laying obviously deceased on the ground with Damian stood over him, nudging him with his foot and holding a gun.*
Bruce: oh my- oh my god, Jaylad no please-!
Damian: in my defence he told me the safety was on.
Bruce, crying: JASON PLEASE NOT AGAIN-
Damian: just give him like ten minutes
Bruce: WHAT ARE YOU TALKING ABOUT- OH MY GOD HIS BRAINāS ON THE BATCOMPUTER
Damian: again, not my fault.
Dick walking in: hey whats all the noi- LITTLEWING?!?!!
*ten minutes later, the family is sobbing and Damian is tapping his foot impatiently*
Jason: wooaaaaah, headache. ā¦is everything ok?
Everyone else, devastatingly shocked:
Damian: i shot you in the head and you died again. they panicked.
Jason: ha-ha, funny as always brat. whatād you do, hit me with the butt of the gun or something?
Damian, turning to the others: it is a miracle he ever managed to get his GED.