Vrish 
The entire tournament track


The hijacking of the Kuru tournament into a plot b/w Ashwatthama & Shakuni to try & contrive a victory for Duryodhan. Shakuni suggests making it a battle b/w the different princes, and is backed by Dhritarashtra, who overrules Bheeshma. Bheeshma makes it a rule that a combatant cannot bleed or will be disqualified, something that works against Bhima, rather than Duryodhan.
So they show Duryodhan being introduced, defeating Nakul & Sahadev fairly in battle, attacking Yudisthir from behind, and losing to Bhima just b'cos he was made to bleed.
Then Arjun makes an entry just as filmy as the rest of them, and Drona realizes that Ashwatthama wants to collapse an elephant statue on him. So he takes the bow, releases an arrow and brings down the statue on Arjun. Everybody is shocked, Kunti sheds a tear, an arrow emerges from the rubble and lands under Kunti's tear just in time to collect it & go back to Arjun, who wipes it on his head. Awesome! 😈
He then battles Duryodhan, is frozen by him and Karna intervenes & unfreezes him.
What follows is even more ridiculous. After an exchange of words, Karna reveals his identity as the son of Bheeshma's charioteer, and is instantly insulted by Kripacharya. Adiratha comes and tries to lead him away, and Bhima calls on him to obey his father. Duryodhan declares him king, Bheeshma objects & is overriden by Dhritarashtra once again.
But the height of it is there being an actual battle b/w Arjun & Karna, and it's only when Karna is struck & his armor becomes visible that Kunti recognizes him.
The original story, in case anybody has forgotten and is just going by what they showed: the tournament took place, the only one Duryodhan fought was Bhima, the fight was broken up by Ashwatthama b'cos it was getting too violent, then Arjun came & showed what he could do. When Drona declared him the world's greatest archer, that was when Karna appeared in order to contest that claim, and replicated all of Arjun's feats. Kunti recognized Karna from his armor, which was visible w/o his being struck, and fainted. Duryodhan seized his chance, and declared Karna a friend. Karna expressed his desire to battle Arjun, and then the question of his origin came up. Duryodhan had him crowned ruler of Anga, Adirath came & congratulated him, Bhima then called him on being a sutaputra, and took Arjun away. By then, it was also sunset, so no opportunity for a battle.
Had the events happened as shown, Karna's whole relationship w/ the Pandavas may well have been different.
Vrish 
There are many, but the one that took the cake was Subhadra, of all people, being introduced of all times, to Kunti, of all people, by Dushala, of all people.
Never mind that Kunti was Subhadra's aunt, and in such a setting, would probably have been introduced by Krishna, had he been around. Never mind that Dushala & Subhadra could never have met - Dushala probably got married b/w the Lakshagriha episode and Draupadi's marriage, whereas Subhadra never came to Hastinapur before the war, and only came to Indraprastha after her own marriage to Arjun. Never mind that she had never heard of Arjun until his visit to Dwarka.
Yet, Duhsala tells Kunti that Subhadra was her friend from Kanyavas, itself a fictitious institution, since princesses got educated @ home, in the palace, and didn't have a whole host of other princesses to befriend.
It's okay for Arjun to get his wife later, like in the original story. But try telling that to the CVs.
Vrish 

While there have been aggressive new contenders for this title, this award this time goes to an entire group - the 6 sons of Kunti. While the kid Pandavas were more or less fine, something suddenly happened once the adults took over.
First of all, all the Pandavas were superior warriors to any of the Kauravas - there is no way any of them would have lost to the Kauravas - even Nakul or Sahadev. However, they showed Duryodhan defeating 4 of them - 2 of them in straight fights, 1 by cheating and 1 on a technicality.
Second, the rudeness of the older Pandavas. Karna is visiting their mother (itself fictional) and the Pandavas intervene and separate them. Kunti tells them to be polite when talking to him, and Nakul makes a sarcastic remark about Karna being a brother like Duryodhan. Finally, Bhima stamps on a lotus that Karna had placed @ Kunti's feet.
Third, the intrusiveness of Karna. In the original story, he did challenge Arjun, but only when Drona declared Arjun to be the greatest of archers. While they retained that theme here, Karna made his entry by first unfreezing Duryodhan, making it look like he picked sides against the Pandavas even before things started. Also, when he met Kunti, he bluntly declared Arjun his enemy, even though nothing had happened b/w them for that to be the case. The veena episode where he takes the initiative in insulting Arjun unprovoked was totally out of character: in reality, it was the Pandavas who usually insulted Karna first, exceptions being w/ Draupadi, both @ her swayamvara and during the game of dice.
Fourth, Arjun being depicted as the leader of the Pandavas, which he never was. It was always led by Yudisthir, and Bhima was second; Arjun always took third place. In the Kurukshetra war, Arjun was put at the head of the army by Dhrishtadyumna, but he wasn't a normal leader of all 5 Pandavas, the way they show.
Finally, Arjun asking Subhadra, in a conversation, whether Krishna thinks he knows everything. Need one say more?
All in all, the characterization of Kunti and all her sons has been a disaster, and with it, much of the serial since the exit of the beloved kid Pandavas and their father Pandu.