Speaking for myself personally, I tend to imagine a lot more personality/backstory for some of the characters I create, more than what actually makes it into the game through name, art, vfx, voicelines, and flavortext.

Often times, this just comes up in an interview or something, or is just added direction to give the voice actor, etc.

One of the Primes is heavily inspired by a particular major character from Mass Effect. Can you guess which one and which character?