"The villains are fortified on this formerly deserted island. We need a hero to get in there and take them out. Unfortunately they have strong air defenses so the attack must come from the sea." A police chief explains to a group of heroes.
"I could glide in there easily with a transparent wingsuit." Toru offers, only to get looks of derision and some light laughter from the other heroes and policemen.
"We will send in Froppy." The police decided before ending the meeting.
"Midoriya, I need your help." Toru asks as Izuku walks out of the police station.
"You want people to take you seriously as more than just a stealth hero." Izuku says knowingly. "Don't worry, I have an idea. Have you ever considered if you can refract more than just visible light? Or if you can store light over time?"
"I haven't." Toru admits.
"Well, I know just the mad inventor that can get all the training equipment we need." Izuku says enthusiastically.
"On second thought." Toru says lamely.
"Don't worry, Mei's never hurt anyone permanently." Izuku says.
If people could see Toru's face they would have called for help.
A few weeks later, after a few failed attempts on the island.
"These villains are terrorists!" A politician shouts, "don't worry about staying non-lethal, just take them out!"
"Of course." The police chief says.
"Well, now's your chance to shine." Izuku whispers.
"Yep, I'll stop by Mei's lab then glide in with the setting sun to my back." Toru replies.
It was another dull evening for the villainous grunts as they patrolled their island fortress while watching another sunset.
"What's that?" A thug asks, pointing at the sun.
"I don't see nothing." Another thug says after taking a look.
"Must have been a bird." The first thug says calmly.
"Those stupid seagulls shouldn't scare you lot." A more important looking thug comments.
"They stole my lunch once, so they became it." A fat thug proclaims, patting his belly.
As they were chuckling a whooshing noise was heard and a pair of thugs were launched off the wall.
"A wind blast?" The important thug asks, "Did they finally send Small Might?"
"I don't see anything in the water." A thug says, squinting against the setting sun. This saved him as the rest were blinded by a sudden flash of light and taken out in short order.
"Invisible girl?" he wonders out loud, "How desperate are they?"
Those were his last words as an invisible leg sent him off the side unconscious and into the sea.
Soon enough the alarm was sounded and the villains rushed into the central courtyard.
"Come out, come out, wherever you are little hero. The last three failed against us and you won't do any better Invisible Girl!" a villain with a tall commanding hat shouts.
"They must be dumping there has beens on us to free themselves from paying them." A thug comments. "Too bad we're keeping them alive."
"Yeah, All that overtime will bankrupt the Hero Public Safety Commission." Another thug adds.
"Hey, don't tell them our plans until we capture them." The leader stage whispers.
'I can't believe how stupid villains have been recently.' Toru thinks as she walks right up to the leader silently.
"Sorry General, but it's not like Invisible Girl can beat us and escape." the thug says.
"Yeah, we didn't see any boats and all of ours are through us." a thug adds.
"Silence!" the 'General' shouts. "She's invisible so we have to hear her!"
"You've done a bad job of that." Toru says casually.
"What!?" The 'General' shouts, grabbing at the air in front of him.
"Solar Flare!" Toru shouts, releasing all the built up UV radiation she had absorbed throughout the day.
Screams of pain and shouts of "My eyes!" filled the courtyard as the thugs writhed in pain, their bodies covered in a terrible sunburn and their eyes in equally bad shape.
"That hurt!" a big thug shouts. "But my regeneration quirk is too strong for you!"
"Is it now? Let's kick it up a notch then!" Toru says with a slightly sadistic giggle, she knew she was going to win and she couldn't wait to rub it in to all her doubters.
"You're just a normal girl, you can't fight there muscles built in record time with my instant results workouts!" The thug shouts before charging the epicenter of the UV attack.
"Assuming I didn't move." Toru says from a position to the side of the thugs' charge. The thug stopped surprisingly quickly and turned to rush her voice. "And assuming I don't have more tricks."
"Some light won't stop me!" the thug shouts, charging wildly.
"I have more than just normal light." Toru explains cheerfully, "Radioactive Beam!"
An invisible force slams into the charging thug and his regeneration goes on overdrive as it's polluted by cancer.
"You probably won't die from that." Toru claims, "but you should probably get to a hospital."
The thug could only moan.
In the leaky dungeons of the island fortress Tsu shivered. The guards had rushed out a moment ago, so she expected either rescue or another prisoner. What she didn't expect was the door to open on it's own and a laser beam to appear out of nowhere and cut her free.
"Wait. Toru?" Tsu asks.
"That's me." Toru replies.
"Get out of here." Tsu says urgently. "They are tougher than they look, tell them to send Izuku."
"That won't be necessary." Toru says happily, "I took care of them."
"Now is not the time." Tsu begins.
"I'm serious." Toru says, voice suddenly a lot cooler.
"Oh. I see." Tsu manages.
"Let's go." Toru says, walking off.
AN: The third installment? Of sorts to this series. It's a bit darker but poor Toru gets ignored by everyone, I wouldn't be surprised if she had some resentment. I've had the idea for her quirk for a while, but it took a story where Toru chose to go villain for me to get this idea based on her reasons. Traitor's Requiem by Syber_Slash was the source.
Manipulating all sorts of light has a lot of potential, gamma rays to burn through everything, x-rays for long term damage, and interesting pictures. Microwaves for food and crowd control and more...