So trueee
Well, Linden had regrets for killing his brother that were affecting his life ╮(￣▽￣)╭
There was a thing back then though wasnt it. The reason why the whole family gets slaugjtered is that its also a punishment to stop their bloodline and erase their existence and also prevent any future bloodshed that their future generations might do
So its p normal to execute the whole family
Yes. It was normal back in that Era for whole families to be killed if they committed treason. Which is what they are doing.
The most tragic thing about about the whole matter may be that in the original timeline this dickhead Marquess and his sister get their entire family, including Michael and Yulian, slaughtered by Linden. Their children didn't have anything to do with the Empress and Princess' murder and even feel that their family was the guilty party, yet Linden kills them too by association. I know they are part of an enemy family, but it's still sort of hypocritical of Linden.