This process also included keeping a journal for the character’s backstory, something that Michael B. Jordan also tends to do for his film roles in the first place, according to his interview on The Breakfast Club radio show.
Knowing how close to his family Michael B. Jordan is, the process to create Killmonger’s psyche for Black Panther obviously gave the world a different version of the man they’ve come to know and love since his early performances in films like Fruitvale Station and That Awkward Moment.
With his tragic backstory involving both the death of his father and the incarceration / death of his mother leading to a rough and painful childhood, Jordan had to separate himself from those he loved to really cultivate the attitude of going it alone in the world for some time.