That was actually the one The last clue was going to be about being corrupted by Odium. Kudos for guessing Nightblood with your first guess and getting outrageously close!
Not the terminating Taravangian
Not the death-dealing Dalinar
Not the assassinating Szeth son Neturo
Not the reaping Rashek
1. This character has killed many
2. This character has had no lines on screen
So
1. This character is of low rank
2. This character has power over others
3. This character is not invested whatsoever
4. This character is dead
hmmm.... Camon?
It is not The gourmand The Lopen
It is not the distilling Ico
It is not the stew savoring Szeth
It is not the roasting Rock
It IS the cooking Kiin, Dreok Crushthroat!
The band name Smashmouth was also a clue. The round is yours!