Illumi is proud and arrogant, cold-blooded and ruthless, stubborn and persistent in achieving his goals. Illumi's moral values ​​are shifted from the generally accepted ones towards the prevalence of his own ambitions, Illumi respects his father Silva, honors his mother Kikyo, and is protective of his younger brother Killua. Illumi's only "friend" is Hisoka, and they repeatedly come to each other's aid