A/N - Again, thank you to Zayden StormVoid, for the quirk ideas. At least two of them, of the amphibious variety, will be shown here
Also, people have been asking how Izuku copied Tsu's quirk, before knocking her up. I'm sorry I didn't specify this sooner, but he copies the mother's quirk as soon as he get their DNA (milk) and he gets his kids quirks, when he makes them.
-x-
"Grrr! Where is he!"
A girl with brown hair and wolf ears growled, as she cast her blue eyes around the hallway.
"I thought you said he'd be here!?" Another girl with long black hair and brown eyes, yelled at her companion.
The first girl snarled at the other as canine growls rumbled up from her throat.
"I can still smell him somewhere around here! Keep looking, he's probably- THERE HE GOES!" she yelled as she charged down the hallway on all fours after Izuku with the other girl hot on her heels.
A moment passed after they were out of sight, before part of the wall turned green and peeled back, to reveal the smushed flat and toad like face of Izuku. His expression appearing almost board or deadpan, as he peeled himself off the wall.
"Kiro" he crooked, before his eyes widened in response and he clamped a hand over his mouth.
Izuku quickly reverted back to normal. His body filling out and his face returning to normal, as he expressed shock and embarrassment.
"Ok...so the croaking and deadpan is a quirk thing. Not a verbal tick or personality trait" Izuku muttered before shaking his head free, as his double ran as fast as he could, far away from the real Izuku.
"I'm so glad I looked up different types of frogs and toads after meeting Tsu and learning about her quirk" Izuku muttered with a relived sigh. He might not have been able to come up with enough quirks for their kids otherwise.
Speaking of which, he was going to need to come up with some more ideas if Tsu was serious about wanting more and not just feeling the effects of the hormones flooding her system.
The idea of coming up with new quirks, actually exited Izuku, but he shook his head clear as he focused on moving through the building without getting caught.
And on that note, Izuku's skin suddenly turned mint green while his hair turned a little lighter, with it staying darker at the tips.
Izuku then crouched down and hoped to the ceiling, where he clung to it like a frog. His skin glistening with the paralytic poison of a dart frog, in case anyone did spot and try to grab him.
Fortunately Izuku had already switched off all the lights in the hallways with Nezu's help, and the ceilings were very high, to accommodate quirks that increased body size.
So, Izuku began silently crawling along the ceiling, unnoticed by the frantic girls who didn't have enhanced senses.
His destination, one of the exits to UA's main building, which was currently guarded by a pair of more coherent girls, who were lying in wait for him.
It would seam Ryukyu was right. The girls he knew socially, and therefor the ones who actually had a crush on him, were effected by his quirk more then the rest.
Even so, dismissing his previous double and producing another one, was more then enough to send the poor girls running after him.
Izuku waited a moment and sniffed the air to see if anyone else was close by.
Once he was sure he was in the clear, he silently dropped down into a crouch before standing up and letting his quirk fade as he looked to the doors.
Izuku then held up his hand and his fingernails turned metallic, before five jacks sprung out. One for each finger.
Izuku quickly plunged his fingers into the wall to his right and winced as he felt a jolt from the electrical wiring he jacked into.
He then closed his eyes as he felt the information fill his head. Part of the local network that ran the school's security was laid bare before him and Izuku mentally imputed the passcodes Nezu gave him, giving him full access to the system.
A massive blast door, then shut over the entrance, locking this part of the building down and trapping the girls in here with him.
As much as the idea embarrassed and mortified him, Nezu was right. With most of the girls gathered in one place where he could control their movements, Izuku could... work through them... more efficiently...
Izuku grimaced. Both at the situation he found himself in and the view he got from the security cameras.
Momo had fortified her position well. Unless one of the hero corse girls or a pro showed up, then no one was getting to her. And even then, it would take some time.
The issue was, Momo's defenses would only remain non-lethal, so long as the other girls understood to stay back. But the others we're getting more desperate and the cannons and spike pits were not going to dissuade them much longer. And Izuku had no desire to watch a medically accurate Home Alone.
Especially when considering why some of them were trying to get to Momo in the first place.
Admittedly, most were just hoping to catch him and Momo in the act, and ambush them there. But a few were really aiming for the explosives.
Izuku needed to move fast, before anyone got hurt.
So, Izuku ripped his fingers free and shook his head clear, before running back down the hallway.
Izuku skidded to a halt though, as he heard and smelled more girls running down the hallway.
"I need to shutter the windows before they realize I'm locking them in and think I'm just planning on leaving them in here" Izuku muttered as he looked around for a solution.
It was then that one come to him, like a sign from above, as the air conditioning kicked on and Izuku looked up at the vent.
"Perfect" he muttered as he used Tsu's quirk to hop up and stick to the wall, where he stuck out a finger and, instead of a jack, a small screwdriver head piped out and spun like a drill.
Izuku grinned as he looked down at the quirk he gave his and Jiro's child. The one that basically made his fingers high-tech swish army knives. A common misconception was that Jiro's quirk was completely sound based, but it was actually tech based, with a focus of sound based abilities as the resulting power.
Izuku almost lost himself reminiscing about his girls and their kids, but pulled himself back to reality, as he undid the vent cover and looked inside.
It was too small for the average human to fit, but for Izuku it would be no issue, as green fur grew over his body.
As the girls ran passed, arguing with each other about which way they saw Izuku run, they completely missed the vent cover, hanging loosely by a single screw, as a tiny, adorable little green bunny, hopped his way through the ducts while dragging his shirt and pants along with his mouth.
"I still can't believe this quirk didn't mutate into something else" Izuku thought as his little nose worked to sniff out where everyone was and his ears flicked back and forth.
This was another quirk from his second time impregnating Mirko, and he'd been both delirious and running out of ideas. Even as he made it, he had been afraid the quirk wouldn't form right, since he hadn't yet been with anyone with a size changing quirk.
Ochako's quirk helped a lot thankfully, since it was gravity based, but that was only part of the equation.
Fortunately for him and his daughter, the quirk formed perfectly. Now Izuku and his future little girl, could become ether giant or mini rabbits.
And by giant, Izuku actually meant giant, as in the size of a car. Not just big like the actual breeds of rabbits that could grow as big as dogs. Though that too, was an option...
Izuku shook himself free of his musings again, as he continued to hop along, occasionally activating his X-Ray vision to see where he needed to go, before twisting and turning through the maze of ductwork with speed, and even hopping up a few levels.
Izuku suddenly gave a panicked squeak though, as he skidded to a stop and contorted his body around the lasers that activated.
"Shit! Nezu's security is crazy!" Izuku thought with strain, as he balanced on his front, right paw. His body trembling with pain and effort, as he bent in ways a rabbit wasn't meant too.
Izuku's eyes darted around as they glowed and he looked for a way out, that wouldn't result in him being barbecued, gassed, impaled, cut to ribbons, or blown to bits.
Nezu truly, was not locking for creativity when it came to traps.
"There!" Izuku thought as his eyes locked onto a weak spot and green lightning arched across his tiny, adorable body, making his fur stand on end, before he vanished in the blink of an eye.
A hole was suddenly punched through the wall to the security room, and Izuku landed on his feet.
BOOM!
Izuku winced and laid his ears back, as a muffled explosion went off. He looked back to see flames, poison gas, and the flashes of what he could only assume were lasers, leaking out through the hole he made.
Izuku winced again, as crushing and grinding sounds fallowed. Soon joined by a chainsaw and a repeated smashing sound and finally a number of spikes poking out of the wall.
"Note to self... never sneak through the vents again..." Izuku thought as he gave a sigh that came out more like a squeak, before he shook his head and turned to the clothes he'd dragged with him.
He then hopped to the back of them and crawled into the shirt, where he deactivated the quirk. His body growing back to normal size, with his shirt already on him and he quickly pulled on the pants too, as he stood up.
Izuku flexed his fingers and tested his human appendages, before letting out a breath of relief and looking to the computers that controlled everything.
Most were smashed, and the ones that weren't, were infected with some kind of virus.
Hatsume had apparently trashed the main building's security before it could lock her inside, which was why Izuku had to go around and close everything manually.
He could still access the systems that were just smashed though, and not infected.
So, Izuku marched up to a broken computer and plugged his fingers into the brain.
Izuku shut his eyes for a moment, then gave a satisfied grunt, as he heard the shutters around the building, all slamming down over the windows and causing the girls to all yelp in surprise and confusion.
Izuku quickly yanked his fingers free though. The smarter and less frenzied girls, would now know where he was, so he needed to move fast.
Izuku let his skin turn mint green again, as he opened the door and hopped onto the wall, before hopping to the ceiling, where he then hopped further down the hallway, bouncing from wall to wall.
Izuku slowed down and clung to the ceiling when he noticed some girls running his way, then picked up the pace again as they passed.
Izuku would have preferred the rabbit form, but in confined spaces like this, the frog was more useful and less prone to brake walls and floors as he bounced between them. The poison skin was a useful backup plan too, and also...
...
Mirko wasn't joking when she said her quirk gave her the instincts of a rabbit, and Izuku was no different when using it. It took all of his willpower not to give in to those instincts, on top of his native quirk's impulses and smash the first girl he saw.
Yah, Izuku was sticking with the frog quirks he got, until things calmed down a little or if things got serious.
Izuku need to focus on the task at hand. So he continued to make his way up the building until he reached the top floor.
He needed to deal with this particular girl next, before anyone got hurt.
The big problem was, Izuku had now locked down all the exits, and this floor was packed full of girls.
He needed a way to get passed them without being noticed...
...
Or better yet, he could just clear them out and get some privacy.
So, with that in mind, Izuku leaped to the ceiling just outside the staircase and camouflaged himself before dismissing his last double so he could make another one.
The double stood below the original and took a deep breath as he watched the crowd trying to get to the roof.
The double then gave a high pitched whistle, catching everyone's attention.
"Hay everybody, I'm right here!" he called out while trying to strike a masculine pose...
It half worked...
...
Izuku was so awkward, it was almost painful to look at, even when high on Izuku's pheromones.
On the other hand, Izuku was RIPPED and Nezu had given him a gym shirt that was a few sizes smaller then normal, which caused his normally hidden muscles to bulge out.
Combine that with his quirk, and a fountain of drool was poring from a number of girls' mouth, before they all erupted into a frenzy.
"Ah!" Izuku's double yelped, as he leaped back from one of the girls that charged at him, while foaming at the mouth. The double then proceeded to suicide jump, down the gap in the middle of the staircase, using float at the last minute to soften the impact, before taking off running. Once he was out of sight, he puffed into green smoke.
The real Izuku waited until the sound of frenzied girls died down, before hopping to the floor and shivering.
"I must not be caught by a large group of them" he muttered with dead eyes. The horrible results of such an outcome obvious and terrifying to him.
Izuku shook his head and walked up to where the girls were all congregated and saw a no-man's land, of a hallway. Riddled with holes and craters from the girls many attempts to brake through the traps set along the way, and the cartoonishly large cannon at the end.
Izuku gulped as he slowly made his way through the hallway. Skittishly watching for any traps.
"Ah!" Izuku yelped as a trapdoor opened and a net gun popped up, but didn't fire.
Izuku held still as it aimed at him for a moment before returning to it's previous position.
Izuku blinked in confusion, but jumped again, as the door at the end opened up.
It would seam she knew he was coming.
Izuku swallowed hard as he steeled himself and marched down the hallway to the open door, with light spilling into the dark hallway.
As he stepped through and he adjusted to the light, Izuku's eyes bugged out, as he found himself on the roof, but he wouldn't have been able to tell if he didn't already know where he was going.
A large red tent, hung over the entirety of the roof he was standing on, providing shelter and near complete privacy, save for their silhouettes. The ground was covered with several large, soft rugs, with candles lit on stands all over the place...
And there was a trail of fake, cloth rose petals, leading to a gold crested, king sized bed with vails covering it all all sides, leaving only a silhouette visible inside.
A very curvy and well endowed silhouette, laying on the soft mattress, covered in fake rose petals.
"Hello Izu~ I've been waiting for you~"