Meruem is the King of the Chimera Ants, a race of beings capable of adapting any genes they eat. Being the King, Meruem is greatly overpowered as he has immense Nen and power. He also has three royal guards, each being powerful and useful to the King.
Meruem, through out the earlier stages of his life, was a evil King who sees himself as being the only King in the world and detest the "fake Kings" who imitate him. Meruem also detest the system of the royal bloods inheriting the role of King as he thinks it should earned only by power. He is overconfident and filled with pride from his immense power and easily kill those who don't obey him or has no value without any hesitation.
As his life progress, he gets bored being King and takes a liking to board games. He calls out the best out of the best and challenges them to a board game. As they lose, Meruem would kill them for not living up to their names. Meruem later encounters a girl named Komugi who would, with no effort, beat him in Gungi, a board game they played.
He later began developing emotions he never felt as he play more and more with Komugi. He becomes more compassionate and respectable as each round ends in a loss. Meruem started to show feelings to Komugi as when he kills a eagle attacking her, this makes him think strength doesn't come in power only.
When Isaac Netero, the chairman of the hunter association, challenges Meruem to a battle, Meruem refuses and requests a talk. Meruem annouces he will spare Netero if he backs down and 1% of the human population as he thinks a minority of humanity has a value like Komugi
Powers and Abilities
Due to being the King of the Chimera Ants, he has a great amount of nen which surpasses the average human.
His nen ability allows him to take the nen abilities of those he has devour.
Due to being a Chimera Ant, he has the strength, speed, reflexes and defenses which is far beyond that of a human