Why is big brother so forceful?

Adeline's eldest brother is distinct from the other three in that he often shows a maturity corresponding to his position, albeit interposed with flashes of malice that corrode any of Adeline's built-up good will. Big Brother, along with his other two natural brothers, is forced to have an outdated hairstyle and wear antiquated clothes, leading to much ridicule from their classmates. Although he takes up the banner of rebellion against Niang, his resolve is extinguished by his stepmother's all-encompassing influence.

Big Brother shows flashes of compassion towards his younger siblings and has a bond with his fellow brothers. However, he instigates many of Adeline's misfortunes, as seen in the case of the urine orange juice and the death of PLT. At the end of the day, Big Brother's character is left unsatisfactorily underdeveloped, considering the difficult balance that is expected of him, a leader among his siblings but a subordinate towards an unjust mother.