Here's chapter three. I don't have much more to say other than enjoy.
Looking back up, his hand still on fire, Izuku was confused when he saw All Might both in pain and smoking. "Satania, what's going on?"
"Calm down," said Satania. "He just ran out of time today. He's changing back to his civilian form".
"Civilian form?" repeated Izuku as he saw the shrunken form of his favorite hero.
"How did you know?" asked the shrunken form of All Might.
"Know what?" asked Satania. "Your name or your injury?"
"Both," answered All Might, or Yagi based on Satania.
"I already told you," said Izuku. "Satania is the devil. Also known as Satan, Lucifer, Beelzebub, and other names, she is the prince or princess of darkness"
"I love it when you flatter me," said Satania jokingly. "Please talk about me more".
"In order to walk among us humans, she had to take a human form," explained Izuku. "Because of this, she is weaker, but she still have her near omnipotent knowledge".
"I have trouble believing your story," admitted Yagi, causing Izuku to shrug. "Regardless, I expect both of you to keep this information secret. Don't even share it online anonymously". Izuku nodded, but Satania shrugged.
"Sorry, but I'm not promising anything," said Satania. "While Izuku still safely make promises, due to being only half-demon, I can't make reckless promises".
"Fine," said Yagi. "I won't force you to do something you're not comfortable with". He took a moment to lift his shirt, revealing a nasty purple wound on his stomach. Izuku listened as Yagi explain his injuries and about a secret battle that he asked to be kept hidden. "As for your question, I believe that even a demon could be a hero if they used their power responsibly".
"Thank you, sir," said Izuku. "I've been having doubts for a while, but hearing you say that I can help relieve most of them".
"Okay," said Yagi as he stood up. "Now I need to get this guy to the police". Patting his pocket, Yagi began panicking when he didn't feel the bottles. Hearing an explosion, both Izuku and Yagi turned to see a pillar of smoke. Yagi quickly ran down the building stairs while Izuku turned to Satania. When he saw that she had already left, he growled before leaping off the side of the building. Using his quirk to slow his fall, Izuku landed on the sidewalk and began running toward the smoke.
"Goddamn it, Satania," cursed Izuku as he arrived at the scene of the smoke. He cursed again when he saw that not only was the destruction caused by his target, but the sludge villain also captured Bakugo. Using his enhanced demonic speed and reflexes, Izuku rushed forward before the heroes could stop him. Igniting his knife with his blue hellfire, Izuku performed several slashes on the villain. He made sure that Bakugo wasn't hit because he would probably feel some discomfort or pain from the hellfire. Unfortunately, it didn't seem to do much. While the flame clearly hurt the villain, any cuts Izuku made was quickly covered up. Seeing as how his current plan wasn't working, Izuku changed strategies. "Bakugo, I'm going to get you out. It may hurt, but I need you to stay as still as possible". Before Bakugo could even try to respond, Izuku was slashing at the villain again. This time however, he was aiming around Bakugo's trapped body. It took nearly half of a minute, but Izuku managed to get his childhood friend free. Now you're probably wondering just what the heroes were doing during all this. The short answer is nothing. They were too busy waiting for the right quirk. 'It's funny that both times a villain attack a person close to me, both Death Arms and Backdraft are there'.
"I didn't need your damn help, Deku," said Bakugo as he took deep breaths. "I could have gotten out myself".
"I know you could have, Kacchan," said Izuku with a smile. "I thought that I should pay your family back for taking me in".
"Stupid Deku," muttered Bakugo as he walked toward the heroes. "After this shit is over, you are going to tell me everything".
"Sound like I don't have a choice," replied Izuku as he cut off several more tendrils. Oh yeah, while Izuku and Bakugo was talking, the sludge villain was still attacking.
"Damn right you don't," shouted Bakugo. 'Dammit, my quirk is practically at max power now, but all that struggling have left me exhausted.' Bakugo growled as he watched Izuku continuously cutting off tendrils. 'He can't finish off that fucker if he constantly defending himself'. Doing some quick thinking, Bakugo figured how to both give Izuku the opening he needed and relieve any debt he had. Even though he will deny it, Izuku just saved his life and he owed him one. 'While I may not have the energy to fight, I can still help'. Bakugo lifted up his hands and yelled, "DEKU!"
"Oh shit," cursed Izuku as he saw what Bakugo was about to do. Covering his eyes, Izuku could still hear and feel Bakugo using his quirk to create a flashbang-like explosion. "Thanks Kacchan," Izuku said as he lifted up both hands and fired a large stream of hellfire at the sludge villain. He listen as the villain screeched in pain, but didn't stop until the sound quieted down. Eventually it did and Izuku turned off his quirk, revealing the injured and unconscious form of the sludge villain. Turning back to Bakugo and the other heroes, Izuku saw that both Yagi and Satania was standing among the civilians. He gave both of them a nod as he tried to leave with Bakugo. The heroes however didn't seem to like that idea and tried to stop them. Izuku and Bakugo listened as they tried to lectured them. When Kamui said that it was dangerous pretending to be a hero, Izuku chuckled and responded with, "I would rather have a pretend hero that help people then a real hero that let people suffer while they wait for the right quirk". With that said, Izuku left, only stopping briefly to tell Satania that the mission was complete. He could hear the heroes shouting at him and Bakugo's footsteps, but he simply just kept on walking.
End of chapter. If I haven't made it obvious yet, Izuku won't get All for One. If you have any questions, like how is Izuku only half-demon?, leave a review or message me. I try to respond to question as I see them.