Note- Aswatthama is not an Avatar of Lord Shiva in this story. He is a good archer but not very good. Here he is greedy, ambitious and selfish. If you are an Aswatthama fan, sorry to disappoint you as Aswatthama is going to be another antagonist in this story. 

The next day in the early morning Aswatthama went to the place he chose to test Brahmmastra. H stood by the bank of the river and chanted the mantras to evoke Brahmmastra. Then Brahmmastra appeared and Aswatthama launched the weapon towards the river. The weapon was so powerful that he himself was shaking. When the weapon was shot at river Ganga, he tried to return it back. But he failed. The weapon was completely out of control and its effect started creating destruction to the river as well as to nearby places. The water started drying up, fishes and other aquatic animals were dying. The shockwave created an earthquake which shook the land and the wave reached Karna's village as well.

Karna was doing his morning prayers like every day. Suddenly he felt a burst of energy. Being an expert he easily recognized the effects of Brahmmastra. He concentrated his mind and identify the location of the weapon. So he ran towards it and when he reached that place, he saw Aswatthama laid down on the ground and the entire area was shaking. Karna was also shocked to see the condition of Ganga. So he used his Guru's teaching to nullify the effect. As a master of all weapons, he was able to stop the Brahmmastra quickly. Then he went near Aswatthama.

Aswatthama's POV,

 'When the ground started shaking I laid on the ground. I know the weapon is too powerful for me and I cannot control it. I can feel the temperature is rising. I thought that I was going to die but suddenly everything was stopped. I looked up and then I saw a young man standing in front of me. He is one of the most handsome men I have ever seen in my life. But the man looks very angry. He comes near me and says, "How dare you evoke Brahmmastra without knowing how to control it? Don't you know it is forbidden to test this weapon without making oneself properly trained? If I did not nullify its effect do you have any idea what will happen then? The entire city will be destroyed." 

Before I comprehended everything that happened, his words struck my head " If I did not nullify its effect". How did he do that? He stopped Brhammastra. How is it even possible? I looked at him again. He dressed in a simple dhoti and white angvastra. But he has a unique radiance. Before I asked him anything, he helped me to stand and asked again. "Does your father Guru Drona knows about your foolish act? I don't think so but can you return back to the palace by yourself or you need my help?" I just shook my head no as I have my chariot and I can manage back home. Then the mysterious man again said, "These celestial weapons are not something to play with, prepare yourself properly and then try to even think about them. Otherwise I have to do something that you won't like." Then he turned to go back.' POV end.

Karna (thinking), 'Just can't believe it. How could the son of Dronachraya be so stupid? Oh, God! Mata Ganga, I almost forgot about her. Her condition is very bad. I need to do something.' Suddenly he heard Aswatthama calling him, 'Hey you....How dare you talk to me like that. Do you know who I am? BTW you looked like a villager, how do you know about celestial weapons and most importantly how did you manage to control it?'

Karna (irritated), 'Yes I am a poor villager who has more brain than you. And for your kind information, I know about the weapons a little bit. You high-class Kshatriyas may forget your manners but I remember, so YOU ARE WELCOME FOR SAVING YOU ASWATTHAMA, SON OF DRONACHARAYA.' Saying that he went to the side of the river. Then he remembered a special mantra taught by Guru Shukracharya-the Sanjivani Mantra that can not only revive the dead but can also heal the injured. But his Guru asked him not to use it without his consent, so Karna closed his eyes and prayed to his Guru to allow him to heal Mata Ganga. 

Shukracharya (in mind), 'Putra, I am giving you permission to heal Devi Ganga as she is important to maintain life on earth and both humans and Asuras need her.'

Then Karna chanted the mantra and slowly Devi Ganga healed. The water turned normal again and the aquatic lives were also restored. Then without giving Aswatthama a second glance Karna left from there.

Hastinapur Palace

When Aswatthama returned he saw the entire palace was already awake from the earthquake. Both Dronacharya and Bheesm stood on the gate. 

Dronacharya, 'What have you done Aswatthama? I told you not to use the weapons as you are not ready.' 

Aswatthama lied,' But father I stopped the weapons.'

Bhism, 'Don't you dare to lie in front of us. First, you committed a grave sin by insulting the blessing of Lord Brahma and now you are lying as well.'

Drona, 'Aswatthama, I am very disappointed. From today I forbid you to use any celestial weapons. If you even try without my content, my curse will destroy you. Now go inside, I don't wanna see your face.'

Aswatthama angrily went to his room. Bheesma asked. 'But Guru Drona, who stopped Brahhmmastra? It is not easy to stop that weapon, in fact, only a few of us know the technique.'

Drona, 'I don't know, here only me, you and Arjuna know the technique, but it is not Arjuna as even he also does not have the ability to stop Brahmmastra that quickly and its neither I nor you. So then who? But one thing is clear, whoever it is must be very powerful. The only person who can do it is our Guru Lord Parshuram himself.'

Bheesm, 'We need to ask you son about the entire incident.'

Later in the morning,

The entire city was alarmed about the incident. Somehow the news was spread that Aswatthama tried to evoke Brahmmamstra and an unknown power stopped it. The common people were very angry at the royalties but did not have the courage to say it loudly.

Hastinapur court

Bhisma interrogated Aswatthama and he narrated the entire story. All the Kuru elders were angry at him but did not say anything because of Guru Drona. But everyone was curious about the mystery man. Aswatthama told him that he was from a nearby village who wore clothes like common Suta but had some unique kundals in his ear. Then Yudhishtir remembered the person they met before the war. He told Pitamaha about him. But everyone was skeptical.

Bheem, 'Come on Jyasht, are you trying to say that a Suta stopped the weapon. That's impossible.'

Duryodhana, 'Why not, we can just send our soldiers to find out who is he? BTW who told you Vrikodar that a Suta cannot do that. Maybe he received weapons training.'

Drona, 'Weapon training is forbidden to the Suta cast.'

Duryodhana (muttering), 'You and your caste system. As if you guys are the noblest and others are nothing. When I become the king I will allow everyone to learn anything they want.' 

King Dhritarashtra sent his soldiers to find the mystery man. He asked them to look at Adhirath's house especially. While Shakuni was thinking, 'I think I found my weapon. One who can stop Brhammastra can do anything. I need to find him soon and make him my ally.'

Yudhisthir informed them that person with a unique kundal was Adhirath's son. The soldiers went to the stable first and found Adhirath there. After asking him, they decided to go to his house to arrest his son. But Karna has already reached the palace. He knew that after the entire episode Pandavas will definitely identify his kundals and told the king about him. He did not want to create any problems for his foster family. So he surrendered himself and the soldiers brought him in front of King Dhritarashtra. 

The entire court was shocked to see a Sutaputra had the ability to stop Bhammastra. 

Bheesm, 'So you stopped the weapon?'

Karna, 'I Mahamahim, otherwise the entire city will be destroyed.'

Drona, 'Lies. How could a Suta have the ability to know about the divine weapon rather than controlling it.'

Karna .'I am not lying. Please ask your son. And I heard that Mahamantri Vidur has the ability to identify people's lies. Am I telling the truth Mahamantri.'

Vidur, 'From what I can understand, you are telling the truth.'

Vidur (thinking), 'He is not an ordinary man. He has radiance like the Gods. But how is it possible?'

Drona (shouting), 'I don't believe you. And even if you stopped the divine weapon, you have one a grave sin. Don't you know Sutas are not allowed to touch weapons?'

Karna (smiling), 'Dronacharyaji, you are a great scholar, I am an ordinary person who does not have much knowledge about vedas and scripts. But can you please enlighten the sabha that from which Shastra you get the information that weapons are not allowed in Sutas hand.'

Now everyone were shocked. All heard about this law from childhood but no one knew about the source. Bheesma himself was a student of Guru Brihaspati and his guru taught him that Varnaved was done on the basis of Karma (work) and Gun (talent), not on birth. But when he returned to Hastinapur, he blindly followed the rule of his kingdom where the lower caste people had to choose their professions based on their birth status. So today when someone asked him directly about the source of this law he remembered his Guru's words 'Putra, always respect people based on their good nature and talents not due to their birth or positions.'

Drona (angrily), 'How dare you asking me questions? My king, I demand exemplary punishment for him. In fact, we shall find that teacher who gave him the weapon training. we shall punish him as well so that no one in future will have the audacity to break the rule.'

Shakuni, 'Guru Drona we will definitely punish him and his Guru but first of all please give him the answer. It is the rule of Kuru royal court that even the biggest criminals can defend themselves and the ministers shall answer his questions. So, which Veda or Puran depicted the law that Suta's are not allowed to have weapons training.'

Drona, 'In Veda there is stated that a man shall do the work based on the status.'

Karna, 'It says status Acharya, not birth status. In some puran it is also stated that the work of a person depends on his talent or interest. A person can change his varna by trainings and penance. Do you forget about Rishi Viswamitra who was a khstriya by birth but turned himself into a Brahmin by penance?'

Aswatthama, 'You...A Suta is giving us lectures. My father is right he and his teacher both shall be punished. Tell me you Suta.. who is your weapon teacher.'

A voice from behind rattled everyone in the court, 'I AM HIS WEAPON TEACHER.' 

Next episode- Fight between Karna and Arjun.