Izuku knew that he didn't have the best luck, so when he got a call from his mom about what she could do about Bubaigawara Jin he took it for what it was and helped his mom to help Bubaigawara, he was overjoyed when he got the call that Bubaigawara was going to take the job.
Bubaigawara was something Izuku had been searching for, his quirk: Double would allow Izuku to do something most people could only dream of, being in two places at once but better since he could be in three places since Bubaigawara's quirk's limit was two copies.
Izuku hadn't told his mom about that second part because he wanted to ask Bubaigawara this in person, he had no idea how the man would take his request and preferred asking such a thing in person.
Bubaigawara was quite receptive to the other part of the job to his surprise but Izuku supposed that he was paying the man more than enough to not question such things, or it might have been being revealed as the Deku-Sensei because the man nearly had a coronary after Izuku introduced himself as that.
Given he was technically a wanted criminal Izuku had asked him for an alias for the legal issues and the man settled on the name Twice after some arguing with himself, which was a touch concerning so Izuku would have to look into getting Maddison to talk with Twice.
But more than anything Izuku was glad to have two more of himself running around that he hardly cared he was going to finish the structural engineering degree so soon, granted six months was much longer than most of his degrees but it was shorter than he hoped, at least he could get prepped for his next degree sooner, he also had to deal with there being three of him in a single room but he adjusted to that quickly enough.
Since he was indulging in his less than savory side of his clients more often than not and employing less than legal characters it was only natural to consider a law degree, and if it had anything to do with his rescue efforts with Tenko and Kurogiri than that was his business.
Kurogiri's wrap gate had already given him over five more hours to do his research/aid but having two free and able body clones who could focus solely on researching and his business while he was studying was a major boon to his cause.
Then when it was time to start his work in the red-light districts Izuku could send the two clones off to other districts so that three places were getting his help at the same time, it wasn't a totally perfect system admittedly since he couldn't link minds with the clones and would have to read both of their cliff notes to know what they did and learn what did each day... for now, he had the Vespas looking for someone that could do a mind-link.
Having three bodies would also help hide him further from All For One since his men would get the wrong idea of his "quirk" and likely wouldn't know which one of him was the real him, something that would hopefully dissuade his men and buy Izuku just a bit more time.
Izuku's clones plan had bore fruit not even a week later, while he was studying and Mido (the business-clone) was working on personal project he had been side-lining, Riya (his research-clone) thought he had found where Tenko's quirk came from and if he was correct it would give them a major foothold with Tenko.
Tenko's quirk was pretty distinctive so there would have to be mention of it somewhere in the world and Riya had been able to focus on that angle without any distractions, he had narrowed it down to a couple of suspects but he personally believed the quirk belonged to one of the first generation of Japanese "heroes", one of the most revered heroes of his day actually, known only in the history books by his codename: Midas.
Accurate data from that point in history was hard to get normally but the government kept good records of the first generation of heroes and you just needed to know where to find it and the Vespas were one of those places, so Izuku got his hands on a copy of Midas's file and while it was gut-churning to read some parts as he was reminded of that times point of view of quirked people it had ultimately sold him on Tenko having that specific quirk.
Midas's quirk was merely called Decay, an Old-world immune system quirk that severely dehydrated the man in question leaving his skin so dry it peeled off in large patches from his constant scratching, and while it gave Midas the ability to reduce almost anything to dust or mushy pulp as the case may be with organic matter that was more liquid than solid.
Keyword almost.
According to their research the rabid quirk made immune system only had one weakness, in a weird twist of evolution the quirk didn't work on two-toes and the antibodies that tore things apart would quickly die off since they wouldn't "eat" anything from a quirkless human.
This oddity was what made Midas such a valuable asset at the time because they could throw Midas at any small town or city and he'd destroy everything but the quirkless civilians and allies left standing, and since his own quirk would kill him without continuous treatment they didn't have to worry about him defecting like other heroes would have.
And if their quirks weren't similar enough for Izuku to be convinced Midas had been listed as missing after a raid by the MLA on a government site and was considered KIA despite there being no body since no trace of him was found with the MLA after the fact.
All Izuku would have to do to confirm or deny whether Tenko was given Decay was a simple test that he could perform in person, since he knew Kurogiri wasn't going to rat him out to All For One the hitch would be how to convince Tenko to play along without revealing to Tenko what he was doing since Tenko was still in too deep to listen to reason.
"You seem more lively today master Tomura, I suppose you're excited for your test?" Kurogiri mused after Tomura glanced at the clock for the fifth time in two minutes.
Tomura huffed but he wasn't so irate that he'd stop smiling "Of course I am, and it's a skill trial Giri." Tomura corrected before turning back to his game.
He had some doubts about Greenzilla's suggested side quest at first given how vague the NPC was but Deku was one of those characters that earned their place and were more than they appear.
Once Deku switched tactics his Exp gains were bountiful, and he was tripling his attributes. His intelligence had gone up like he expected and there were a ton of new cheat codes Deku gave him for the daily quest list.
His charisma was way higher than it was before and he had no idea how he bumbled along before as the pitiful mage/rouge he was before, his DPS probably and Giri being such an effective bard too.
And the loot. Deku gave the best loot hands-down, the shoes were a good cosmetic but most of the loot he got from Deku didn't just look cool it came with a stat bonus, the hoodie he was wearing right now had a +5 stealth and the new gloves he wore gave a +8 to his dexterity.
He had definitely owed Greenzilla a decent amount of loot for prompting such a great side quest while he waited for more story episodes from Sensei.
So, when Deku told him during their last session he had gained enough points to take a skill trial to possibly get an interaction that was normally unavailable for his class how could he not be ecstatic?
Tomura had tried to buffer out Deku's respawn time by playing one of the games Deku suggested but his mind couldn't help wondering just what new options he was going to gain if he completed the skill trial.
That was another thing he liked about his minigames with Deku, he could always backtrack and beat his high score on them, he didn't have to be worried if he failed it because it wasn't a quick time event unlike the doctor's stupid puzzle mini games.
Honestly it was like that man wanted him to fail with how unhelpful he was to Tomura's level grinding, and he didn't respawn regularly like Deku so Tomura had to spend some of his resources to summon the geezer, it was just not worth when he could just do Deku's (much more fun) route instead.
Tomura's head shot up once Kurogiri got a text alert and he rushed to get to a save point, Deku was going to spawn soon, and he did not need to be distracted from his skill trial.
He had just managed to close his game and get the console to start it's shut down when Kurogiri opened the portal and Deku walked into the bar.
Tomura's excitement grew when he saw Deku had foregone his regular outfit and usual emoticons for something a bit more serious and held an odd box in his hands and Tomura leaned forward in his seat just a bit.
Deku walked over to the bar and sat down on the stool across from him before addressing him "Shigaraki Tomura, are you ready for your trial?" Deku prompted.
Tomura grinned "Yes." he readily confirmed but Deku seemed unmoved.
"This trial contains a decision that will permanently effect your character's story arc, be aware that if you accept this trial your choices will have permanent consequences that cannot be undone. Do you still wish to continue?" Deku questioned and Tomura's eyes grew wide.
Deku had explained to him that he'd have to face story changing decisions that would affect the main story about a month after he got Deku as a DLC character but he didn't think he be faced with one so quickly, he must be plowing through Deku's story line faster than he thought.
"Yes." Tomura confirmed, the anticipation almost killing him at this point and he had no idea when he'd get another event again because as Deku explained these sorts of things were one's you'd likely lose forever if you passed on them.
Deku opened the box, and when Tomura glanced inside saw an even odder looking green glass ball that wasn't much bigger than his palm, Tomura wouldn't lie that he wasn't too sure what to think, he raised an eye and looked up at Deku knowing it would prompt a hint.
"Tomura, remove the glove from one hand." Deku instructed, taking him greatly aback.
The gloves Deku gave him were hardly taken off ever, his quirk was just too destructive and while he still used his quirk often Tomura preferred to not breaking his gaming stuff because Giri had been willing to buy him the good stuff since he stopped throwing the controllers.
"To continue the trial, you must remove the gloves, or forfeit the trial." Deku commented.
Frowning Tomura took off his right glove and placed it on the counter, Deku nodded at the action.
"You must pick up the orb then touch it with all five fingers to complete the trial." Deku told him.
Tomura scowled at that remark, compared to what he was expecting from Deku that was so... dull.
He probably only had himself to blame though he guessed with a sigh, he had over hyped the event and made his expectations too high, even if Deku was a compelling character so far most games had one or two duds, even the really great ones.
Disappointed Tomura reached in for the green orb and held it up for Deku to see before he placed his ring finger down on it, fully expecting for the dinky hollow ball to do what every does when he touches it and turn to dust.
Expect it didn't.
Tomura disappointment was gone in a flash as he stared at the ball, blinking Tomura lifted his ring finger then again placed it down and was even more bewildered when it still didn't crumble away after.
Tomura turned to Deku "How?" he muttered utterly lost, because up until now the only thing that hasn't been destroyed by his quirk was Sensei, and that was because he had a special quirk that prevented his quirk from working on him, something this orb could not have.
Deku merely smiled back at him "Congratulates Shigaraki Tomura, you have completed the trial of Midas and have gain the passive skill: Quirkless Ally, this skill gives you the ability to safely touch any quirkless person without causing harm via your quirk at the cost of never being able to use your quirk on a quirkless person again." Deku informed him.
Tomura's mouth opened a bit and the orb slipped from his grip, shattering on the floor "What?" he questioned.
Instead of repeating his dialog like normal Deku merely reached out and pressed their fingertips together, Tomura instinctively clenched his hand around Deku's and his breath caught waiting to feel as Deku's hand turned to a bloody pulp.
However, after nearly a minute nothing happened and all Tomura could feel was how warm Deku's hand was. A bit dazed he couldn't help gawking at their hands, when was the last time he had held anyone's hand without needing a glove?
Maybe before he got his quirk? But he couldn't remember that time so it didn't count, he couldn't remember holding Sensei's hand since he had been with Giri most of his life, and Giri didn't even have proper hands to hold so he couldn't count either.
Cautiously Tomura swiped his thumb across the back of Deku's hand, marveling at the uneven different texture, he couldn't even place it in his mind what another person's skin felt like. When Deku returned the gesture Tomura jolted at the sensation it left in its wake, and he shuddered.
Remembering something from a few games Tomura let go of Deku's hand and reached forward to try and ruffle Deku's hair but froze with his hand teasingly close to the fluff as years of people falling reared up in his mind.
Deku however didn't hesitate to press his face forward and immediately Tomura felt how soft Deku's hair was, which wasn't news to him since he had felt the boy's hair a couple of times before when he was messing with Deku, but it felt different now that his hand didn't have a glove on it.
Tomura admittedly got sucked into playing with Deku's hair for a who knows how long before what he doing really sunk in.
He could touch someone again, Deku had found some way to counter his quirk and he now he could hold a person's hand without them falling apart before his eyes.
Tomura didn't know why but the thought of reaching out to someone and being able to hug them made his heart race, or why it made his eyes start to water but in a hazy of sorts without thinking he rushed forward to hug the only person close enough to.
Deku didn't fight and just hugged him back.
It took him a moment to realize he was crying, why? He didn't know, but for some reason he was, and it felt right? It didn't feel bad so he didn't try to skip the cutscene he had prompted.
Eventually Tomura got his emotions back in check and pulled away from Deku, a touch embarrassed for his overreaction, Deku was a good sport about it but said their session would be ending early.
Tomura supposed that was fair, finding this skill for Tomura likely took a pretty chunk of Deku's assets to acquire and neither of them would have the stamina for a quick session after the cutscene they had.
Giri had already cleaned up the shattered orb and moved on to sending Deku home to start his cool-down period, a 36 hour wait period before Giri could respawn him was long, but Deku was worth it and gave him the time to do the quests and tasks Deku gave him.
And though he was tired he couldn't help also being excited with the new skill he had been given, his quirk might not be as strong with a debuff that wouldn't harm a fraction of people and given it was a permanent one he couldn't reconsider his choice to gain it.
He could still kill quirkless people, just not with his quirk anymore which wasn't all the bad in hindsight, his quirk wasn't that effective as he thought even at full strength because it was a slow and painful death for whoever he touched. Maybe useful for torture but Deku had explained that it wasn't as great of a tool as Sensei and the doctor believed it was.
Shortly after he thought this a realization came to Tomura.
Quirkless ally was a skill that only gave him the ability to touch quirkless people safely, he had touched Deku and nothing happened to him, which meant that Deku had to be...
"Sensei can never know about Deku." he whispered his heart plummeting.
Tomura had ordered Giri not to tell Sensei about his side questing because he wanted to surprise him with his progress, and a part of him had hoped that he could impress Sensei by forming his own connections and doing something without needing to be guided every step of the way.
He was even certain that Sensei would approve of Deku and recruit him with how smart he was during the war-strategy games but now that he knew Deku was quirkless Tomura knew he would have to hide Deku from him.
A memory from far back, one of his first that he could clearly recall with certainty, well before Sensei's big battle with All Might, Sensei had lead a homeless man in the doctor's lab and sent him off with the doctor.
He had remembered asking for the man's name and Sensei chuckling at him before ruffing his hair and saying "Don't bother Tomura, he won't be around long. He's quirkless."
Sensei was a great man and Tomura was grateful for him even when he didn't always understand why he did things the way he did, but Tomura knew Sensei didn't like the quirkless, he had watched as Sensei lackies would gather them up kicking and screaming without a care in the world because of how often it happened.
Even if he asked for it Sensei would not listen to him and leave Deku to his own devices, at best if Tomura really pushed his luck he could convince Sensei to make Deku into a low class Nomu that could retain his old personality but then he wouldn't be able to touch Deku again because he would not be quirkless anymore unless he could also get Sensei to give Deku a quirk for it.
And as cool as a Nomu skin could be for Deku he much preferred his NPC as he was, Tomura had yet to fully explore Deku's story line and there were plenty of hints that Deku had a rich lore he'd miss out on if Sensei killed/turned Deku.
"Master Tomura?" Giri called snapping him out of his thoughts.
"I'm ordering you to not speak about Deku to Sensei Kurogiri." Tomura snapped, it wouldn't be much but Giri never disobeyed an order.
Giri stared at him for a moment "So long as he doesn't order me otherwise, I shall uphold your request Master Tomura." Giri cooly replied, and Tomura frowned.
Giri's answer was disappointing but expected, he never stood up to Sensei but this was likely the best Tomura could have hoped for, so he said nothing and turned to stare at his right hand, the phantom sensations still tingling his nerves.
So this comes from my personal theory of how Tenko's quirk works, that the way he turns things to dust is a superpowered immune system powered by his quirk, sort of like an auto-immune system disorder.
And by touching something with all five fingers he spreads the anti-bodies which upon "smelling" anything not a non-quirked human tear it apart by eating it and leaving the grey ash once they die off, and the reason he's so itchy and has dry skin is because the anti-bodies need a lot of water and are suckking him dry because he doesn't drink enough water.