Also if i remember there was no empress in novel , only consorts .
The ml's father actually supported him but hated the fl and tried to kill her many times and there was mention of ml's brother but no such name was there only that emperor tolerated and supported the ml actually because ml had leverage he was competent and only he could be the crown prince the rest brothers were no good .
There was no plot of ml's mother suspicious death , also the sister was half sister of ml , on whom the emperor doted the most because she was the only child of the consort the emperor loved the most.
Also the sml was pretty lenient not abusive towards the sfl and very much in love with fl , no shady dealings .
The fl was also shown as pretty naive in beginning who uptil half of the novel loved the sml and hated ml they had this total push and pull thing , ml was a red flag sometimes in novel , half of the the time doubting the fl , and being jealous of sml even thinking fl wore red cause she wanted to distract all enemies of sml to herself during battles but she wore it as blood cannot be seen in red color dress.
Also the sml was a eunuch there , not at all interested in power and was blackmailed by empress dowager who knew his secret to gove up throne to his half brother