Saitama wasn't sure why he woke up but a quick glance around the apartment showed that there was nothing out of the ordinary. He glanced at the digital clock on the TV and rolled over with a groan. 3:44 am.

He spared a look at Genos curled up on the futon next to his own. His disciple had pulled the blanket up to his ears so that there was only an unruly mop of blond hair visible and his even breaths indicated that he was still sound asleep.

Well, then. Saitama wriggled back into his nest of blankets and closed his eyes.

Ten minutes later he was completely frustrated, bone-deep-tired and entirely unable to fall asleep. Just as he considered turning on the small lamp and continuing to read his action manga, he heard Genos' breathing speed up. A shudder ran through his metallic frame and then the young cyborg started whimpering softly.

Ah, shoot, nightmare. Saitama debated whether to wait it out or wake his disciple. His selfish side urged him to rescue Genos out of the clutches of whatever horror scenario his brain had spun up so Saitama would have something to do other than staring at the ceiling in the dark.

Genos jerked. „No... Mom, no..."

Involuntarily Saitama's eyes widened. That was definitely not fair. Genos didn't have to relive losing his home, family and body.

Mind made up, Saitama sat up and reached over. „Hey, Genos. Wake up."

His hand connected with a shoulder and he gently shook – next thing he knew, Saitama was on his back with 300+ kg of killing intent on top of him, one hand around his throat, the other raised and glowing.

„Oh", Saitama remarked.

His voice seemed to snap Genos out of whatever trance he was in.

„S-sensei?" The cyborg's voice was rough and confused. Golden eyes widened in shock and Genos immediately scrambled off his teacher, bowing with his head pressed all the way to the floor. „Forgive me, sensei."

Saitama waved a hand. „It's fine. Good reflexes, by the way."

Genos was staring down at his hands and suddenly stiffened with a choked noise. His shoulders were trembling so violently that Saitama heard a faint metallic rattle.

„Huh? You okay?"

Genos looked up with gritted teeth, pain written in every line of his body. „It's just – agh – this happens sometimes..." He cut himself off and bit down on a whimper.

Saitama felt lost. He placed his hands on Genos' shoulders. „What's wrong? Is there anything I can do?"

Genos took a shaky breath and visibly reined himself in. „It's a natural response from my central nervous system to the d-dream I just haaa-had. I'm not in any physical danger, it's just phantom pain."

Saitama's face lit up in understanding. „Is there anything I can do?", he asked hesitantly as Genos doubled over with a stifled moan, clutching at his chest.

„N-no..."

All his strength, and yet Saitama was completely powerless to help his obviously suffering roommate. Phantom pain, huh? And that from pretty much every part of the body...

„At least lie down, Genos, you look horrible." Aiding his unsteady disciple back to the futon, Saitama dumped a blanket on top of him. Genos curled up, panting through gritted teeth, eyes squeezed shut.

„Uh, you said this happens often?" That statement really had Saitama worried.

A shudder ran through Genos' body and he needed a few seconds to stop the involuntary choked noises he was making before he found the composure to answer.

„It is a risk of cybernetic s-surgery."

When Genos was still quietly writhing on the futon, Saitama felt a tug at his heart and hesitantly stretched out a hand and started to rub circles onto his tensed back. „Does this help?" A shaky nod, so Saitama continued.

Slowly, Genos calmed down and relaxed inch by inch. Finally, the tense lines in his face eased up and his clenched fists opened.

„Whew, you had me scared there."

„Sorry, sensei", Genos hoarsely said, his voice just a tad unsteady. At a loss, Saitama got up and puttered to the kitchen. „I'll make tea."

Genos was clearly in a miserable state, yet he still pushed himself up. „I'll do it, sensei! It's my fault you're awake anyway!"

Saitama eyed the cyborg's shaking hands and shook his head. „Nah, I'm good. You go sit down."

When the tea was finished and Saitama returned with the steaming pot and two mugs, Genos was curled into a pathetic lump underneath the blanket, hugging his pillow to his chest.

God, he's only 19, Saitama thought, suddenly feeling old and jaded.

Hearing his sensei's footsteps approach, Genos sat up and gladly wrapped his hands around the mug. The young cyborg mumbled his thanks and then stared into the murky green liquid as if it held the deepest secrets of the universe.

Saitama cleared his throat, remembering Genos bubbling out his backstory when he first showed up at the apartment. „So, um, you wanna talk about it?"

Genos swallowed. „Uh, not particularily."

Saitama was relieved. After all, he wasn't exactly qualified as a grief counselor. „All right. Just some questions: How often do you have those nightmares?"

Genos shrugged and took another sip of tea. „Depends. Sometimes I go for weeks without one, sometimes it's pretty much every night. Lately, it has gotten better since I moved in with sensei, though."

„Okay. Have you talked to your doctor about those episodes?"

A dark chuckle. „Of course. He witnessed them too many times to count."

„Ah. And there's nothing he can do? No medication or something?"

Genos gave him a look. „You can't medicate something that's not there. The pain is purely psychosomatic. It's my brain thinking my human body is still attached and shredded to pieces after the attack of the mad cyborg, when in reality those neural pathways don't exist anymore in the first place."

Saitama let that sink in. „I see. That sucks."

Genos huffed out a laugh and wholeheartedly agreed. „Yes, it does."

After that episode, Saitama made a mental note to ask Doctor Kuseno about it whenever he saw him next. He wanted to know whether there was anything he could do to help since the scientist knew a lot more about how Genos' body worked.

The occasion when he next came in contact with Kuseno was, as usual, carrying a torn up cyborg disciple to the lab.

Genos had been knocked around a fair bit and had been sort of woozy after the asshole monster used his head to blow a hole into a skyscraper. Genos had drawled something about „jus' a concussion, sensei, don' worry" but combined with the mangled right shoulder and deep gouges in the armor plates covering Genos' chest, Saitama had dragged him to the doctor.

Kuseno had checked on Genos, fixed the shoulder and promised to have new plating ready in the morning, then stuffed Genos into a bed and ordered him to rest.

Then, Saitama found himself standing a few metres away from where his disciple was calmly sleeping and looking at the doctor who was watching over the bundled up figure on the bed with a slight smile.

Saitama awkwardly coughed. „Uh, Doctor? Can I ask you something?"

Kuseno moved to stand beside him and cocked his head. „Sure, go ahead."

Saitama described the situation he had found himself in after Genos' nightmare and Kuseno knowingly nodded.

„I'm only going to tell you this once, so listen carefully. Genos here is one of the strongest people I know. You have no idea in what condition I found him after the attack. I honestly don't know how he was still alive. His legs were crushed underneath the wreckage of his family's house, one arm torn off, his face and torso burned. There was an iron spike from a street lamp piercing his chest. He had lost so much blood that it was a miracle his heart was still beating when I found him. I only recognized the poor boy by the bit of singed blond hair that was left. First, I thought he was dead, but then I heard him sob and shout for his family. I couldn't just watch, so I sedated him, dug him out and got him to my lab. Stabilizing him was out of the question, his body wouldn't heal from this. But I couldn't just perform cybernetic surgery of this magnitude on him without his consent. I knew it was morally wrong, but instead of giving him morphine and letting him die in peace, I shot him full of stimulants and asked him whether he wanted to live on as a cyborg. I'm aware that he wasn't exactly mentally stable then, his body shutting down and his mind still clouded by shock and pain, but his answer was unmistakable. I worked two days on his new body, a prototype stubbed together by what I had at hand. When I was sure he would survive, I buried what was left of his human body."

„I helped him through his rehabilitation but Genos refused to talk to a therapist. By now I do think of him as something similar to a grandson so it was breaking my heart to try to ignore his sobbing at night or all the times he woke up screaming. Genos poured his entire mind into killing the mad cyborg and that determination is what keeps him going. I am glad he met you – he actually mellowed a bit around those sharp edges. He is still hell-bent on avenging all the lives that monster took but nowadays he takes better care of himself and finally took an interest in something else."

Then, Kuseno levelled a glare at Saitama. „Genos put all of his faith in you, so don't you dare disappoint him. If you break his heart, I will hunt you down. Consider this is your warning."

Saitama should laugh at being threatened by a mushroom-bowl-cut old scientist, but something in Kuseno's eyes made a cold shudder run down his spine.

„Well, then", Kuseno sunnily continued as if nothing had happened. „Once Genos has fulfilled his quest for vengeance, I could always clone his old human body for him. I kept samples of his DNA, so if he wishes it, I could easily give him his organic body back."

Saitama felt his jaw drop. „What? Really?"

„Genos only cared about combat ability and raw firepower when he got his first updates. It was me who held him back from shedding any human limitations. I wanted him to be able to live as normal a life as possible. There was only one thing he was and still is adamant about: There will never be any altercations to his brain. He could have a lot more sensory input if he chose to do so, but he wants to keep what's left of his humanity."

„Ah, by the way, how much of him are still the original parts? I mean, I've seen him pretty torn apart but.."

„His brain and spinal cord. I hooked up his artificial nervous system to the organic synapses of his spine, so the information would be processed in a natural manner. Of course those organs are protected by armor, but those are still 100% human."

„I wished for him to keep his human heart, but sadly, it stopped twice during the transformation surgery and was too damaged to be transferred. First, he was kept alive by batteries while I perfected the core. He does have artificial lungs and an equivalent of a circulatory system. I am rather proud of that piece of bio-engineering, to be honest."

Saitama nodded. At least now he knew where his disciple had picked up that horrible habit of rambling on in a monologue.

„Hmm, since you asked how to help him: Basically there is nothing you can do besides distracting him from the phantom sensations. Touching him and grounding him in reality helps, that's all I know. And make sure he doesn't overexert himself since those episodes really take a toll on him mentally."

Saitama considered this. Genos always made him tea and looked after his sensei whenever he wasn't feeling well and tried to cheer him up when the public was behaving ungratefully. Saitama had drawn the line at Genos offering to hunt down the people that sent him hate mail, but the cyborg was always the first to stand up and defend Saitama against any accusations. Staying with him when he suffered from those nightmares and flashbacks was a small price to pay considering the effort Genos put in brightening his sensei's every day. „Got it, doc."

So when Saitama next spent a good chunk of the night passing tissues and cookies to his disciple at the anniversary of his family's death when the stubborn teenager refused to go to sleep and he found himself watching over his finally passed out form, he smiled to himself. It felt nice to help someone and actually receive gratitude. Especially when he wasn't thanked for his inexplicable strength but for his support as a person.