This is my first time seeing a donghua character react in a relatable fashion. The king got really pissed, as he should be.

This is exactly the reason why novel is popular. Characters are down to the ground, especially MC. He is not a good guy and he is not a bad guy, he always acts like normal person would... and that is... the way that works for him, selfish as any normal person.

One of the best short donghua ever

That's the problem right. This kind of Manhua actually needed a more lengthy Donghua.

The 4 that were gathered (or Congress of soon to be dead men) are opposition of the royal family. And in next episode or two it will be explained why they have no other choice but to look away. but that would be a spoiler

Bruh its his expressions that make it worth while like the situation is intense and this whole time Qin Chen just standing there smirk'n at them, like fool i'm untouchable you old dunce XD.

Ah... well! He who laugh last laugh best. I'm sure MC will help the royal family in despatching those arrogant fools.

#1 short donghua better than ..

The problem with "atoning for their sins" is that this is not about that. It's about trying to "atone for his sins" BY COMITTING MURDER that is the problem. He not only tried to seek revenge without proof of wrongdoing, but then rebelled against the emperor himself while trying to cover up his crime by making the excuse that he was stupid enough to get duped by the "victim".
This emperor is really a sheep in wolf's clothing. He can't do anything about either side, even when he has personally witnessed them committing a crime in the public eye.

remind me of nowadays politics lol, you think the leaders are in charge but it's those tycoons who are pulling the strings so even if you have good intention you will Just have to go with the BS the king in the series. Lot's of realism in the series and the characters play their role well to suit each situation.