(for anyone finding his character off after the flashback just know the joker is a lot of things and an idiot isn't one of them/depending on which version/so you'll have to accept the build up/however despite this I do note the pacing is a bit too slow at the end)
The joker was there surrounded by his men who all had their guns drawn toe joker was smiling sinisterly they were at the penguin's nightclubs.
"come out cobble you know you can't just hide away from me"
The doors of the club exploded with a hail of bullets but his goons were well-armed bringing up reinforced riot shields. when the firing cease the penguin stepped out with his goons.
"I knew this was coming but the rest of them will try to kill you it's been too long"
"hahahaha you know I may not be as skilled as the bat but I came prepared"
joker's men pulled out tubes that released his gas but the penguin and his men put on gas masks as the whole club was filled up.
"looks like you came prepared but the plan wasn't to kill you that way"
"oh really well it doesn't matter"
One of the men in the back picked up a rocket launcher as everyone parted as it was fired it hit something before blowing up clearing most of the gas but as it cleared there wasn't anything there except the chunks of the jokers men. The penguin walked forward checking the bodies as none of them had the attire of the joker.
"where the hell is-"
he was cut off as a knife was stabbed between his legs and with surprising strength he sliced up to his chest as blood splashed everywhere as Oswald dropped in a pool of his own blood.
"sorry old buddy old pal but I'll be meeting you soon I have a ton of others to visit and then we can all have a great party with bats in the afterlife hahahahaha!"
______________________
Isaac woke up as the teacher slammed a folded up paper on the desk "Isaac sleeping in class isn't aloud right now when I'm teaching something important you have to listen up" the teacher scolded before going back up to the board. Isaac looked around at the whole class and sighed in annoyance.
'It would be so easy to just start a fire a lighter, leaving the stoves on high and light a bottle I don't belong with these idiots I need something to make things more interesting but I'm not nearly strong enough to threaten the basic school guards with decent quirks'
Isaac looked outside to see a school guard with a quirk that made with have plated skin.
'What a loss cause I mean I'm ballsy enough to fuck with the S chested boyscout but taking on a bunch of even low powered meta's would mean the end for me but this place is so fucking boring'
In the middle of this little dilemma he was having as if the world it's self was trying to prevent a massacre the school announcements came on.
"Mr Isaac Loi please report to the main office please"
Hearing that Isaac happily got his bag and walked out to the main office not caring about being here at all hoping this was what he thought it was. He opened the doors and the atmosphere suddenly changed everything looked normal but there was a man with white hair and red eyes and looked fairly old but in great shape. The man and Isaac locked eyes and for a moment the man saw through the facade but he didn't bother to expose him. He smirked "so shall we be on our way Isaac we have a lot to discuss it's been a good couple years apart" the man said.
"Sure I don't like being around boy scouts anyway" Isaac remarked his father chuckled a bit "I wouldn't say that about all of them" he said as they walked out.
_____________________
"you know I've never been told your name and I'm dying to know the man who so graciously brought me here" Isaac said the man smirked "well you can just call me dad and I decided to show up to see if you have a quirk which is why we're at the hospital to see a friend".
"oh... can't wait to meet them then"
"well depending on how this visit goes I'll tell and allow you to say my name"
the car was parked in the parking lot and the 2 walked in the hospital the place was bright and had that usual hospital feel despite the place looking big and the lot being lined with vehicles there was no one wait for their appointment or any sounds of activity. The person manning the desk was dressed in casual clothing a Hawaiian shirt and pants and some shades.
' I thought I told them to dress for the part well I'll punish him for his insolence later '
All for one thought but still keeping up the casual act he smiled.
"so is the doctor in today?"
the person sweated a bit as if he knew he fucked up but he answered normally.
"Yeah he's at the first room on the right"
"thank you have a great day"
POV CHANGE
I opened the door and walked through seeing my other men dressed appropriately for their roles though I began to notice how quiet my son was being. I glance at him and he looked like he was in his own world I dismissed it for now and opened the door.
"I hope this wasn't too tedious Dr. Tsubasa I did schedule this way later"
"it's not a problem for me it would have bothered me if I had to wait that long anyway so let get this done quickly"
the doctor grabbed one sringe and smirked.
"are you afraid of needles my boy?"
"I can handle a little poke in the skin sir"
Isaac answered with a slight yawn of boredom.
"hm well then hold still"
~timeskip~
the doctor had injected him with a powerful sleeping medicine and turned to his master.
"you could just tell what his quirk is I don't think it'll be necessary to do the whole process"
"you are right but I want a on hand copy just to have a excuse to taking him for so long"
"that women has outlived her usefulness also I find the kid odd"
"hm your not wrong but it's not a concern yet plus weird isn't a bad thing"
"I'll take your word master"
the doctor picked Isaac up and layed him on a platform with a pillow and turned on the machine which was made by a quirk user with the power of creation capable of fully analysing a person's full biology.(lazy BS? probably)
After going through the machine printed a whole detail document of Isaac's condition Tsubasa read the document and looked shocked.
"you need to see this sir"
he passed the paper to all for one who reading through instead of looking fearful or shocked had a dark smirk on his face.
"it seems like you're right the woman has done enough I'm not considering him as my successor but I'll make sure he's on our side with such a dangerous power as this"
Tsubasa nodded
"that would be wise sir".
All for one picked up his son and disappeared.
(ok laziest cliffhanger ever flame me as much as possible but hey I was in a odd place next time we'll get a year one for the Joker with the context of a 10 year time skip comment what I could have done give more ideas vote if you feel and peace)