Then another shuriken came and hit the guy fighting Sarada, this time it was Konohamaru. He managed to send a shuriken in the gap given by the enemy to look back. The guy fighting Sarada died and she managed to hold the pillar falling on her. While she was about to be relieved,she felt a chill behind her back and turned around. She saw a heavy light aiming to wards her.
It was the reactor. The way this reactor works is it takes the DNA of a person and makes it highly volatile and launch a huge amount of such DNA molecules at high speed. While non living things are destroyed when it hit, living things get influenced - their DNA with it's own DNA. Due to such volatile nature the living organisms usually always end up over mutating into gross looking creatures.
Such a reactor device fully charged was targeting Sarada. Sarada felt a chill behind her back. She can't move because she's holding a heavy pillar and even her legs were stuck to the floor because of the previous fight.
Boruto failed to break through the sturdy defense of the enemy and he couldn't stop the reactor or take care of enemy. He failed at his objectives because he was weak. He saw that the reactor was turning but it wasn't towards him, it was moving towards Sarada who was holding a pillar from falling on her. It was a perfect chance to hit a non moving target and Darui realized that, he just wanted a lab rat to test and he found it.
Boruto rushed towards Sarada and as the reactor was about to shoot, he just went near and made clones to hold the pillar and since her feet were affixed to the ground he pushed Sarada down to sit and held her hands close to her and hugged her from behind with both hands completely covering her from the reactor. He had a larger body frame so it wasn't that hard to cover her and said "Don't move an inch". In a moment, reactor fired the beam.
Sarada didn't move an inch yet cried out loud "Dodge idiot". The pillar was completely vaporized from the reactor fire whereas the beam was also hitting Boruto. Both Mitsuki and Konohamaru were too shocked yet couldn't move due to their own fights. Although Konohamaru had the upper hand and dealt a lot of damage, the enemy wasn't giving him chance to move to help any of them. Mitsuki finally managed to kill one enemy but the other one was persistent in not letting him join his friends.
As the beam fired for a whole second, the pillar vanished the clones were gone only Boruto and Sarada remained. Sarada didn't move and was too astonished by the sheer force as she saw the pillar and clones vanish right in front of her eyes, yet she didn't turn around because she will also face the beam if she does. Whereas Boruto took the direct impact of the Beam from the reactor. Boruto closed his eyes and focused on his Body control while his body started changing visibly in the back, his body was growing disproportionately and slowly getting back continuously.
First his head swelled a lot and then came back to normal, then his back shoulder started to swell 10 times and then went back to normal, the same thing happened to multiple places for the next 2 minutes. After nearly whole 2 minutes everything calmed down, Mitsuki and Konohamaru dealt with their enemies and came near Boruto, they were also too shocked to see Boruto almost swelling and going back to normal again and again.
The scientist was the one who's most surprised because he knows once it swells it's never supposed to go back to normal. After a whole 2 mins, he slowly opened his eyes and let go of Sarada. Sarada immediately moved out of his hug and looked back, she almost felt like she was looking at a person who didn't eat for a week. His face was soo pale that you could mistake him for a beggar who starved to death.
She yelled out "Teacher we need to get him treated". He saw the condition of Boruto and took his pulse and said "He's exhausted but he'll live. Let's feed him some soupy food on the way and have Sakura-san look at him in our Village". Mitsuki said "I'll go get some soupy food, Teacher please deal with that scientist and wrap up here" and went away.
Konohamaru killed the shield enemy and captured the Scientist easily and tied him up. The Scientist who was the most surprised called out to Boruto and asked why are you back to normal. Boruto who barely had any energy yet he gathered some and said "Your machine doesn't seem to be working just like your brain" in a weak tone. Sarada was fuming nearby that she had to carry that bloody scientist back alive.
Konohamaru looked around the place and found a few experimented people alive and the assistants of the scientist. he killed them all, assistants because they helped and experimented people because they can never be human again. He said with pain and pity "The one who made you like this is captured, after torture and interrogation we'll send him to you" and drove a knife in their neck one by one. It was a gruesome job yet he wasn't one to falter.
Then Konohamaru went and informed the client that the job is done and came back and waited together with everyone else for Mitsuki. Mitsuki came in some time and brought food for everyone except the scientist. Sarada took the soupy food from Mitsuki and started feeding Boruto slowly. Mitsuki didn't complain because it was Sarada.
Boruto said in a very low voice "If you were going to feed me this soup, I would've left you there to eat this soup instead of me". Sarada retorted with "You should've done that. No one asked you to play hero" and started feeding Boruto roughly. Boruto was fed 1 bowl and they prepared to leave after having food. Mitsuki was carrying the Scientist and Konohamaru was carrying Boruto very gently.
They managed to reach Konoha in 2 days. They directly went to Hospital and admitted Boruto. Sakura was not there but after some preliminary treatment from Hospital staff Sakura arrived. Konohamaru said that he was hit with some kind of reactor and said that he was like that since that time. Sarada also said how he saved her and that she's alive because of him and stuff like that. Sakura checked Boruto's condition and said "He seems to be stable but he doesn't have an ounce of energy. It will take him a few weeks to recover even with treatment".