One punch man! (Saitama x reader insert)

The Shallow Lake King

"Humans! If you wish not for annihilation, take heed! I bear a message from the depths!" The giant octopus wearing a toga boomed as I walked up to it with Saitama. "You will surrender the surface to us, the Clan of the Seafolk! Thereafter you shall become our nourishment, human scum-"

"This guy is annoying." I mumbled to Saitama as he sighed. The octopus stopped and looked down to see us, bending down and pointing at Saitama.

"Nice head! Are you related to an octopus by any chance?" The octopus complimented as I stifle my laughter. Saitama must've heard me, because he brought back his fist immediately and uppercuts the octopus, leaving only his bottom half left.

"Wow, did he really tick you off that much?" I asked Saitama, picking up a tentacle in disgust. Saitama only huffed and walked away as I dropped the tentacle and flew after him. "I'll take that as a yes."

-timeskip-

We finally stayed home and relaxed, I washed dishes while Genos dried them with Saitama reading manga.

"Sensei. You have finally moved up to rank 2 in Class C. You are on the verge of entering Class B!" Genos said happily as I clapped.

"Class B, huh? That means I won't have any more weekly hero quotas, right?" Saitama asked as I sweatdropped.

"If you see moving up in rank as that, then yes." I answered for him before Genos's phone went off.

"Oh, excuse me..." Genos answered the phone as I walked over to Saitama and kissed his head. "Hello? City J? It is a bit far. Are there no competent heroes nearby?"

"Class S work?" Saitama asked as he turned on the TV. I sighed, having a bad feeling in my stomach.

"Seems like it." I mumbled. Genos came back from the phone call and peeked his head out.

"Sensei and (Y/n)-sensei! The monster you two defeated on your way home the other day called itself one of the 'Seafolk', right?" He asked us as I remembered the octopus.

"I forget." Before Genos could reply to Saitama, we looked over at the TV.

"Several monsters calling themselves the 'Clan of the Seafolk' have appeared in City J and are attacking anyone in sight." The new reporter announced as I sighed.

"A Class A hero fighting them all alone and on the brink of defeat." Genos pointed out before the TV showed the lone hero surrounded by the Seafolk.

"His extreme fatigue and pain are apparent. A prompt response from the Hero Association is desperately needed. The threat level is Tiger. All citizens are asked to stay out of the area." I quickly put on my suit, nodding to the boys as they got ready and we all sped off towards City J.

Saitama and Genos were running as I flew next to them. "How much farther is City J?" Saitama asked as Genos looked towards the skyline of the city.

"We are almost there. But I am getting no readings. I will scout ahead." Genos announced. "Once I have confirmed their location, I will let you guys know."

"Be careful!" I yelled after him as he boosted ahead. Saitama and I kept going until we heard an announcement from the intercoms with a siren.

"This is an announcement from the Hero Association. The threat level is Tiger. All citizens, please stay clear of the area." They ordered as I looked at Saitama with uncertainty.

After a while of running/flying towards City J, we made it as the rain started to downpour, making the feeling in my stomach worse. We walked around before spotting a guy on his bike staring at us.

"Wait, you're... Class C, rank 2 and Class S rank 15." He pointed out as I stared at him in confusion.

"You a hero too?" Saitama asked for both of us as we exchanged looks. "Have you seen Genos?"

"Genos?"

I felt a terrible chill from behind us as I turned around. Something definitely didn't feel right, and there could be lives at stake. I need to go now before it's too late.

"(Y/n)? You okay?" Saitama asked me as I flinched and turned back to him.

"Class C, rank 1, Mumen Rider." I blurted out his name as he gasped and turned to me. "Please take care of Saitama, I need to go before it's too late."